<![CDATA[GroWell]]> Mon, 30 Mar 2015 20:00:20 +0000 hourly 1 <![CDATA[Light Measurement: Lumens, Lux, PAR and Micromoles]]> Tue, 17 Mar 2015 11:12:21 +0000 Spectrum

From looking at a rainbow you can tell that sunlight is made up of different colours. These colours of light can also be differentiated by their wavelength – which is measured in nanometers (nm).

Light spectrum


Lumens & Lux




Lumens are a measurement of light intensity often used to define the output from artificial lights.


One lumen is equal to one candle/candela.


It makes sense to measure light in this manner if you’re assessing how well they help you to see in the dark, but the technique has no real relevance to horticultural grow lamps because lumens relate to human eye sensitivity.


Consequently lumens do not give a correct representation of the properties of a lamp that are useful to plants.



Bright light

Lux is often used by light-measuring devices and simply measures how many lumens fall on each square metre of a surface.


So, an illumination of 50,000 lux is 50,000 lumens falling on each square metre.


Lux measurements are handy for judging the level of intensity of your grow lamps. This can help you to determine a suitable height to position a light above plants and will also give an accurate indication of lamp degradation.


However, lux is still not a particularly good measurement for determining the quality of light or the practicality for growing plants.


PAR, Photons & Micromoles



The human eye is highly sensitive to light around the middle of the visible spectrum, between 500nm and 600nm. Plants find wavelengths between 400nm and 700nm really useful for turning light into energy (photosynthesis) – this has become known as Photosynthetically Active Radiation, commonly abbreviated to PAR.

Human vs plant Whilst the human eye finds light at 555nm the most visible (thus more useful), plants react favourably to two distinct areas of the spectrum – the blue area between 400nm-460nm and the red area between 580nm-700nm.



PhotonsProfessional growers and light manufacturers have switched from measuring light in lumens and lux, to photon count in the PAR area.


Without going into too much detail, a photon is a particle of light.


A blue photon has a short wavelength and a red photon has a long wavelength, with the latter also possessing more energy than the former.


Your plants are only interested in the number of photons – they do not use the energy in the photon for photosynthesis.


A plant requires 8-10 photons to bind one molecule of CO2. So a blue 600W light produces less photons than a red 600W light, and is less efficient for photosynthesis.


To measure photons, you use a device called a quantum meter.

Quantum meter

The total amount of photons emitted from a lamp per second is known as the photosynthetic photon flux (PPF).


Micromoles (µmol)

Photons are counted in micromoles (µmol) – one µmol is 602,214,150,000,000,000 (602 quadrillion) photons!


The unit most commonly used for the photosynthetic photon flux (PPF) is micromole per second (µmol/s). A good 600W HPS lamp will emit 1100 µmol/s.


What exactly is a micromole?

A micromole (µmol) is a unit of measurement used to count the particles/photons of light that plants need to grow and bloom. Micromoles are what cause plants to react to light, and represent the unit of measurement for Photosythetically Active Radiation (PAR).




An ‘Integrating Sphere’ (aka Ulbricht Sphere) is used for calculating lamp output accurately.

Integrating Sphere

The only (slight) issue with PAR

Wavelengths lower than 400nm – e.g. UV-A and UV-B, and higher than 700nm – e.g. infrared and far red, are not taken into consideration. These wavelengths outside of the PAR range have been shown to play a role in plant health, hormone signalling and the formation of beneficial substances such as oils and phytochemcials related to defence against pests. As has become apparent through experiences with products like the Dimlux CDM, a broad spectrum of light can be beneficial for plant health, growth characteristics and production of essential oils. The spectrum of light can be thought of as the plants ‘light diet’, and is an important consideration that PAR measurements exclude.



To summarise, if you have two lights and one registers a higher lumen output, it is not an indication of better plant growing potential. The most useful light output data concerning plant growth is measured in micromoles.


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<![CDATA[Could your plants benefit from a climate control system?]]> Mon, 16 Mar 2015 11:16:54 +0000 Why is climate control important to indoor gardeners?

Bergdorf OptimaLarge scale growers aiming to produce phenomenal plants on a regular basis are guaranteed to get the best results by setting up a sealed off, temperature optimised closed loop grow room - and this is only possible through use of an excellent climate control system.


After installing what is essentially an air conditioning unit, you no longer need to bring in fresh air from the outside (preventing temperature fluctuations and significantly reducing the risk of pests and disease), so desired conditions can be quickly established and easily maintained. The lack of intake activity does require you to manually add the missing CO2, but here you've

actually got the opportunity to supply it at a rate that

will boost growth levels!


If the scale of your ambitions is slightly smaller (but no less important), then a climate control system can be geared towards extra effective management of the environment inside one of the larger models of grow tent. Such flexibility means that plenty of different types of grower are able to enjoy the benefits of this fantastic technology!


What are ‘split’ air conditioning units?

The split type of climate control system consists of two main parts – a compressor that removes hot air from the growing space (typically located outside of a building) and an indoor unit that treats the air inside the growing space. For anyone unable to accommodate an outside unit, we suggest checking out the OptiClimate System.

Split Air Con

Without doubt, the best climate control systems on the market for indoor gardeners are made by Bergdorf. Each of the 3 different models (Standard, GrowMaster and Optima) have been specifically designed to manage the conditions of an indoor grow room - which no other UK unit can claim right now.


Key features of Bergdorf Air Conditioning Units

No engineer required


Bergdorf is the only brand of air conditioners available in the UK that doesn’t require a trained engineer for installation.


Whisper quiet


Unlike the other air conditioning units on the market, Bergdorf Optima and GrowMaster Systems have a whisper quiet function and are designed specifically for grow rooms.


Low powerUniquely, each one of the Bergdorf air conditioning units will only draw the power needed for cooling. The 12,000 BTU has a maximum draw of 1000W, but once the room has reached the target temperature it then starts using less of the compressors capacity and reduces power consumption by up to 75% (drawing as little as 250W). The maximum current draw seen so far from the 21000 BTU Bergdorf Optima at GroWell Wembley is 690W, with the average sitting between 390W and 495W.


Saves time


It is always better to over-spec the air conditioning unit because a more powerful unit takes less time and less energy to achieve the desired temperature settings.


Selecting the required size of air-conditioning unit

To identify a suitable model of air conditioning unit for your grow room, you need to work out the cooling capabilities (measured in British Thermal Units - BTU’s) required to comfortably manage the anticipated levels of heat. This calculation is largely influenced by the power and number of lighting systems being used, so it makes sense to cross-reference BTU’s with total combined wattage of lamps.

BTUs per Watt



ADD 20% just to be on the safe side




SUBTRACT 10% if ballasts are located outside of the grow room

(i.e. in the room next door, not just outside of the tent in the same room)




SUBTRACT 20% if using air-cooled lights




After taking these few points into consideration, the final BTU rating can be calculated. This will already account for heat created by dehumidifiers, air circulators, growth gas generators, etc. If the figure falls below the lowest rated climate control system, simply round up!


Where possible we suggest selecting a 21000 BTU Bergdorf Optima for 4-6 x 600W lights and a 30000 BTU Bergdorf Optima for 8 x 600W lights. Anything bigger in terms of a lighting set up and you should spec two air conditioning units for the room to enable efficient cooling.


TOP TIP: Multiple units can be more effective than a large one (2 x Air-Con Units = 3 x the cooling capacity!)

Increased efficiency EXAMPLE:

For a grow room with 4 x 600W lights, you’d be looking at the following calculation:



1 x 600W grow light = 2400 BTUs

4 x 600W grow light = 9600 BTUs

(4 x 2400 = 9600 BTUs)


20% Safety Buffer

9600 x 0.2 = 1920

9600 + 1920 = 11,520


This set up requires 11,520 BTU’s


The customer now has a choice of 4 products:

Example Options We recommend the last option - this Optima has more features and a larger unit only needs to run for a shorter amount of time to achieve the desired results, which does help to save energy and cut costs.

Code Price Qty
Bergdorf Optima Air Con Unit - 16,000 BTU 7102 Bergdorf Optima Air Con Unit - 16,000 BTU


Choice of air-conditioning units

There are 3 different brands of Bergdorf air conditioning systems. The Standard unit is a great entry level model, whilst the GrowMaster and Optima offer more advanced features such as CO2 dispersion and ultra quiet modes of operation.

Bergdorf Air Con IMPORTANT NOTE:

Purchasing a dehumidifier alongside a Bergdorf Standard or GrowMaster Air-Conditioning System will typically be necessary because the level of humidity tends to rise during the times of day when a unit is programmed to switch off. On the other hand, the Bergdorf Optima Climate Control System has specific night and day settings that account for changes in humidity, so you're less likely to require a separate dehumidifier.

Code Price Qty
Dessicant Dehumidifier - 10 Litres/day 2052 Dessicant Dehumidifier - 10 Litres/day



Each of the OptimaGrowMaster and Standard Split Air-Conditioning Systems from Bergdorf consist of an indoor unit and an outdoor unit.


The indoor unit should always go inside the room or tent.

Closed Loop Room The outdoor unit can be installed in several different ways:


1.) On an external wall or a covered balcony

Outdoor unit This is the traditional method used for most air-con systems


2.) In a nearby spare room, hallway or bathroom

Outdoor unit indoors

Multiple outdoor units can be placed in here for multiple grow rooms


To accommodate multiple units in option 2, ONE of the following steps is required to deal with any of the hot air produced:


A.) Open a window

Multiple outdoor units

B.) Set up an RVK extractor fan


C.) Use one large complete air con system to cool all of the outdoor units in the room, with only the large outdoor unit actually being mounted outside


Introducing CO2

Some growers are running OptiClimate Systems and Split Air Conditioning Units with Exhale CO2 Bags and getting good results, however the most effective method is to use controlled and dosed CO2 enrichments with a Hotbox Growth Gas Generator, a regulator and a Dimlux CO2 Controller. See below for a sizing guide.


We hope that this article serves to whet your appetite for climate control systems. To get further information about them, please feel free to give us a call on 0845 345 5178.

http://www.growell.co.uk/blog/wp-content/uploads/2015/03/ClimateControl_blog-150x150.jpg <![CDATA[Could your plants benefit from a climate control system?]]>
<![CDATA[Take A Shortcut To Success – Maintain A Mother Plant]]> Fri, 13 Feb 2015 14:18:19 +0000 Mother plants provide the stock foundation for many experienced growers. However, if you are new to the concept it can be seen as a confusing and unnecessary luxury. Allow us to simplify matters, by explaining exactly what is involved and the benefits that result from having a decent mother plant.


What is a mother plant?

A mother plant is a plant kept permanently in the vegetative state. Cuttings can then be taken from this plant to produce numerous offspring that are genetically identical – i.e. they share exactly the same properties. Whether you want a continuous stream of heavy yielders, early finishers or easily manageable plants (or plants with other characteristics that are just as valuable to you), it becomes possible because all of the cuttings come from one well-established plant and thereby promise to match the performance of the adult. Suddenly growing from seed seems a lot less appealing, being rather unpredictable and sometimes quite expensive - especially if rare and exotic varieties are involved!

Mother plants

How to select a mother plant

If you have grown from seed before you’ll know that even though the plants are of the same environment, in the same media, and on the same feeding schedule, a small percentage of them always end up outperforming the others. Some tend to sprout up faster, some grow taller and leggier and some just look a little weird! Yet the outlook for these plants could be completely different by the flowering stage! Since cuttings/clones need to be taken during the vegetative stage, it is worth doing so for all of the plants that you intend to put into flowering. Just make sure you carefully label up both the cuttings and the plant they came from for future reference.


The more plants you take cuttings from the wider the selection pool is for your mother. There are many growers out there that have at some point limited themselves to taking cuttings of the best looking plants, only to regret their decision later on when an initially less impressive one suddenly transforms and excels beyond comparison during the flowering stage. Don’t make the same mistake!

Taking cuttings As soon as you have selected a cutting to become your mother plant, you can discard the other candidates – perhaps by flowering them while you allow for it to develop.


What you need to keep a mother plant

Keeping a mother plant is a relatively simple process that will pan out just how you want it to if afforded the right time and attention. Whilst not difficult to manage, you have got to do a little bit more than simply put a light over a plant and wait for the shoots to develop!



Your mother plant requires a dedicated space (like a Small BudBox Grow Tent or an Intermediate BudBox Grow Tent) and a separate light source. There are several options available for the latter including single and multi-tube T5 fluorescent units, a compact fluorescent lamp (cfl) and reflector or even a metal halide bulb – anything of decent quality with light primarily in the blue spectrum. Run the chosen light on a cycle of 18 hours on, 6 hours off to help ensure that the plant remains in a vegetative state.

Mother plant lighting

Although the degree of heat kicked out by propagation lighting is relatively low, to maintain optimum temperatures in a smaller sized tent it definitely still makes sense to have an extraction/filtration unit set up.


When considering a main growing system for this task, the best option is to pick something simple like a RhizoPot (16 litre size and up recommended to give a small-to-medium mother plant enough room to continue growing) with Canna Terra Professional Plus Soil Mix. Start off by building root mass in a Propagation RhizoPot for three or four weeks, then move the plant into the main container.

Code Price Qty
1 Litre Propagation RhizoPot - 8cm x 8cm x 15cm (Height) 2191 1 Litre Propagation RhizoPot - 8cm x 8cm x 15cm (Height)
2 Litre Propagation RhizoPot - 9cm x 9cm x 18cm (Height) 2192 2 Litre Propagation RhizoPot - 9cm x 9cm x 18cm (Height)
16 Litre RhizoPot - 28cm x 28cm x 26cm (Height) 8191 16 Litre RhizoPot - 28cm x 28cm x 26cm (Height)
30 Litre RhizoPot - 35cm x 35cm x 30cm (Height) 8192 30 Litre RhizoPot - 35cm x 35cm x 30cm (Height)
Canna Terra Professional Plus Soil Mix - 50 Litres 1115 Canna Terra Professional Plus Soil Mix - 50 Litres


Alternatively you can use a hydroponics system such as the IWS Oxy-Pot or Brummie Bubbler, but beware that the mother plant will get big really quickly and produce large amounts of cuttings - sometimes proving to be difficult to manage. Coco, on the other hand, doesn’t really suit mother plants because it "locks out" certain elements of the required grow nutrient after approximately 6-8 weeks.



A ‘grow’ feed is required to provide the all-important nitrogen levels, which should be mixed with plenty of water to create a weak nutrient solution (you don't want aggressive growth, the plant just needs to tick over).

Code Price Qty
BioBizz Grow - 1 Litre 0702 BioBizz Grow - 1 Litre
Canna Terra Vega (Grow) - 1 Litre 0730 Canna Terra Vega (Grow) - 1 Litre


In terms of additives, we highly recommend using Cannazym to boost rootzone health and Nitrozyme spray a few days before taking cuttings to encourage a flourish of new growth.

Code Price Qty
Cannazym - 250mls 2000 Cannazym - 250mls
Cannazym - 1 Litre 0798 Cannazym - 1 Litre
Nitrozyme - 100mls 0424 Nitrozyme - 100mls
Nitrozyme - 300mls 0425 Nitrozyme - 300mls



Remember nutrients will need changing every week or two, dead leaves should be removed quickly, and the plant may require a little pruning to remain in good order – plus don’t forget your five day bug check!


To prevent a mother plant from getting too tall and make the best use of grow room space, you may want to try topping/pinching out the main growing tip in the stem using a scalpel. This technique causes the stem to branch off and grow outwards rather than upwards. Over time mother plants inevitably get too big and bushy at which point you can take cuttings from it to create a new one.

Code Price Qty
Disposable Surgical Scalpel - each 0226 Disposable Surgical Scalpel - each


Taking cuttings

Cuttings can be taken anywhere off the mother plant, the lower branches are older and woodier (have less sugar and more carbohydrate) and may root quicker and be less susceptible to rot. The newer top shoots once rooted may grow quicker. Either will make good cuttings. For a more comprehensive guide on taking cuttings check out the following two articles:


- Taking the perfect cuttings

- The Race To Root Cuttings

Using Clonex Lifespan

Once you have a mother plant in place, a bountiful supply of clones seemingly awaits - this should be the case for between 6 months and 3 years. Sometimes after a few months you might find that the plant starts to look a little gnarly and begins underperforming. All is not lost though – you can grow one of your clones and use that as your mother plant! By regularly replacing your mother with a clone, you are able to keep the same genetics and will always have a constant supply of your chosen plant.

http://www.growell.co.uk/blog/wp-content/uploads/2015/02/cover-web-150x150.jpg <![CDATA[Take A Shortcut To Success – Maintain A Mother Plant]]>
<![CDATA[Plant Pot Dynamics: the impact of different shapes, sizes and materials]]> Thu, 12 Feb 2015 15:34:19 +0000 Growing in Pots - The Basics


What is the purpose of putting a plant into a pot?

'Potting up' (also known as 'potting on' and 'transplanting') either involves putting a plant into a proper container for the very first time or moving one on from an existing container to a bigger container. It is a long-established gardening practice – but why exactly? What does it achieve? Here’s a little reminder for you:


- Firstly, the process of potting up helps you to avoid over-saturating the growing media.

Your nutrient solutions can spread over a larger surface area, so roots and their immediate surroundings aren't left soaking wet for prolonged periods of time. Otherwise, you would inevitably face issues relating to rot.


TOP TIP: did you know that the AquaZen Slow Water formulation in SHOGUN Samurai Coco Nutrients will actually aid the flow of nutrient solutions across your chosen growing media? This massively improves the distribution of key elements and makes them available to plants for longer periods of time.


- Secondly, it enables a good root system to grow throughout the entire plant pot.

Sticking with a small container is guaranteed to limit the future progression of your plant because roots simply run out of available space. By giving them a greater freedom to roam and the opportunity to seek out more nutrients and water, you're able to actively encourage development. Potting on

As a result of potting up, your plants can grow in a faster, healthier and more effective manner than if they were confined to just one small size of container.


Are there any drawbacks to putting a small plant straight into a large pot?

Obviously the opposite approach to keeping a developing plant in a compact pot is to quickly let it loose on a much larger one, but this also promises to cause problems! Roots are very direct, racing out towards the edges of the container rather than distributing equally across the entire area. When they fail to penetrate the wall of a plastic or ceramic container, circling starts to happen – ultimately wasting energy and making poor use of the growing media.

Overly big pot A careful and considered strategy for potting up will give roots the opportunity to branch out at each of the stages a new container is introduced, leading to a far more impressive and productive rootzone.

Good practiceGrowing in RhizoPots


Potting up with RhizoPots is still necessary to prevent your growing media from becoming damp and stagnant. However, only 2 potting up stages are required (rather than the usual 3 or 4).

RhizoPots 1.) To begin with you should use Propagation RhizoPots.

These have been designed to accommodate propagation plugs/cubes and let you air-prune roots from the earliest stages of a plant's life, which lays the foundations for a complex root structure.

propagation-rhizopot 2.) Then transplant each Propagation RhizoPot straight into a final RhizoPot.

The roots grow through the sides of the Propagation RhizoPot with ease and continue to air prune at the edges of the larger container.

RhizoPots Pot Size


As you can tell from what has been discussed so far, size clearly matters! Small pots often restrict growth in the long term whilst huge pots are often a waste of resources and space. A good rule to follow is outlined below:


The Rule

Use 50-60 litres of growing media per 600 Watt of light (covering 1-1.2m2).

Pot selector

Pot Shape


A lot of people believe that the shape of a container has a big impact upon drainage (one of the most important factors to consider if you're going to grow in pots). However, it is the properties of the growing media that will ultimately determine how easily nutrient solutions pass through the container and the resulting zone of saturation at the base - known as the ‘perched water table’.


Perched Water Table  

Water is not distributed evenly throughout a pot. Adhesion, cohesion, and capillary action attract water to particles and resist gravity. The ability of the growing media to ‘hold’ water through adhesion and cohesion has been dubbed the ‘matric potential’. It is the same throughout the container.


Gravity pulls water down through the container and out of the drainage holes. While gravity is constant throughout the container, ‘gravitational potential’ registers higher at the top of the container and lower at the bottom.


Due to the gradual decrease in gravitational potential towards the bottom of the container, matric potential can be deemed greater the further down you go, where media particles are able to hold more water. This causes the formation of a perched water table – otherwise known as a layer of saturation – at the bottom of the pot. Different sized pots

Container height affects the relative amount of water versus air. With the same media, the perched water table occurs at the same height, irrespective of the container size. Short containers will have the same perched water table as large containers, thus a greater percentage of container volume is filled with water.


Clay Pebbles And The Perched Water Table

A lot of growers add clay pebbles to the bottom of pots for ‘improved drainage’. Based on the principles of the perched water table, and how the growing media ‘holds’ water, does adding pebbles to improve drainage actually work? More often than not, very little improvement in drainage is achieved – the pebbles just raise the perched water table.

claypebbles So why add clay pebbles? Well, they’re really useful for the following reasons:

- As an insulating barrier for cold floors

- To prevent run-off from being sucked back into the media by capillary action (so you have more time to empty saucers)

- For RhizoPots used in saucers (using a RhizoSystem and putting them on RhizoStands is recommended)

Code Price Qty
Clay Pebbles - 10 Litres 0544 Clay Pebbles - 10 Litres
Clay Pebbles - 45 Litres 0082 Clay Pebbles - 45 Litres


What is the ideal pot shape?

To identify the optimum shape of pot, you first need to take into account your specific circumstances (e.g. the choice of growing system, media, etc).


Typically, for the broadest use (from hand-watering to drip irrigation) you should opt for Pot A.

Ideal pot Why are RhizoPots shorter and more squat than most plastic pots?

Thanks to the fabric material allowing for a faster drying process, the shorter and wider shape of RhizoPots can accommodate higher overall water retention and offset any associated issues (unlike Air-Pots up to the 15L model).


What if someone wants a container that allows the media to hold more water?

When you want higher overall water retention, choose Pot B (e.g. an AquaTray). This is commonly used in drip irrigation systems with rockwool slabs – a growing media that boasts great properties regarding air space and capillary action.


Code Price Qty
1 Litre Propagation RhizoPot - 8cm x 8cm x 15cm (Height) 2191 1 Litre Propagation RhizoPot - 8cm x 8cm x 15cm (Height)
2 Litre Propagation RhizoPot - 9cm x 9cm x 18cm (Height) 2192 2 Litre Propagation RhizoPot - 9cm x 9cm x 18cm (Height)
3.8 Litre RhizoPot - 15cm x 15cm x 19cm (Height) 0792 3.8 Litre RhizoPot - 15cm x 15cm x 19cm (Height)
8 Litre RhizoPot - 21cm x 21cm x 21cm (Height) 8199 8 Litre RhizoPot - 21cm x 21cm x 21cm (Height)
12 Litre RhizoPot - 26cm x 26cm x 22cm (Height) 8190 12 Litre RhizoPot - 26cm x 26cm x 22cm (Height)
16 Litre RhizoPot - 28cm x 28cm x 26cm (Height) 8191 16 Litre RhizoPot - 28cm x 28cm x 26cm (Height)
30 Litre RhizoPot - 35cm x 35cm x 30cm (Height) 8192 30 Litre RhizoPot - 35cm x 35cm x 30cm (Height)
39 Litre RhizoPot - 40cm x 40cm x 30cm (Height) 8193 39 Litre RhizoPot - 40cm x 40cm x 30cm (Height)
56 Litre RhizoPot - 43cm x 43cm x 38cm (Height) 8194 56 Litre RhizoPot - 43cm x 43cm x 38cm (Height)
78 Litre RhizoPot - 50cm x 50cm x 40cm (Height) 8195 78 Litre RhizoPot - 50cm x 50cm x 40cm (Height)


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<![CDATA[Your grow room’s WINTER HEALTH CHECK]]> Wed, 14 Jan 2015 16:36:02 +0000 Grow Room Temperature


Are you monitoring day and night temperatures?

If you don’t currently have any way of measuring the room temperature then that’s the first issue to address. Treat yourself to a Temperature and Humidity Meter, positioning the probe in a suitable location to take accurate readings – e.g. inside ducting or in the shade at the base level of your plants.

Accuread Meter

Code Price Qty
Accuread Temperature and Humidity Meter 0876 Accuread Temperature and Humidity Meter


Have you been hitting target grow room temperatures?

Target room temperatures will vary from one person to another depending on the type of plants being grown. Generally speaking though, you ought to aim for between 24oC and 28oC.

Target temperature Can you generate additional heat indoors?

Indoor temperatures can plummet with little-to-no warning, so gear up to produce more heat. A tubular heater or oil-filled radiator should do the trick!

Tubular Heater

Code Price Qty
80 Watt KlimaHeat Tubular Grow Room Heater 0611 80 Watt KlimaHeat Tubular Grow Room Heater
800W Oil-Filled Grow Room Radiator 7675 800W Oil-Filled Grow Room Radiator
2.5kW Oil-Filled Grow Room Radiator 7676 2.5kW Oil-Filled Grow Room Radiator


Have you completely sealed off your grow room?

You might already have decent heat-generating equipment but still be fighting against freezing conditions upon the arrival of winter. In this case, look to see if you can find any particular areas where cold air is penetrating your growing space. Fill holes in walls and seal gaps between the frames of windows and doors.

Seal up your room Are your lights running at the right time?

Temperatures inevitably drop at night so we always recommend that you run your lights during this period of time. The heat produced by HID lamps is often strong enough to maintain suitable grow room conditions for plants. When they are then switched off and the sun comes up, its warmth will kick in and limit the amount of additional heat required!

Grow at night Do you still draw fresh air into your grow room from outdoors?

During winter you don’t want any plants coming into contact with the cold outside air. Restrict intake activities to indoors only, situating your intake fan and ducting somewhere other than your grow room – e.g. a spare room next door. Temperatures are less likely to decrease and as an extra bonus, any “lived in” air will be high in growth promoting CO2!

Intake fan and ducting For garage set ups, you need to pull in fresher air from the area opposite your growing space and ensure that stale air is extracted outdoors.


Are your plants sat on the floor?

A cold floor can really shock plants growing in pots. To overcome this issue, simply place an upside down Garland Tray underneath them!

Garland Tray

Garland Tray Nutrient Temperature


Are you tracking nutrient solution temperatures?

Certain hydroponics systems such as NFT Gro-Tanks and IWS Oxy-Pots give roots unrestricted access to nutrient solution, which does work wonders to promote rapid growth and substantial development. However, it can also leave them a bit exposed when temperatures take a turn for the worse. Unfortunately cold feeds are harmful to your plants, so make sure you closely monitor the conditions down under. We recommend using an excellent value Accuread Digital Nutrient Thermometer.

Code Price Qty
Accuread Digital Nutrient Thermometer 1213 Accuread Digital Nutrient Thermometer


Have you been hitting target nutrient temperatures?

The ideal temperature for nutrient solutions is between 18oC and 20oC. If you go below this target range you’re inviting trouble and threatening the immediate future of your plants (one or two degrees really can make all the difference). Likewise, a much higher reading also raises cause for concern since it leads to a reduction in dissolved oxygen content – a potential cause of root rot.

Target Temperature Can you raise the temperature in your nutrients?

A sudden drop in nutrient temperatures can be quickly and easily countered as long as you’ve got the right equipment on standby. Nutrient Heaters let you select a preferred temperature and then gently warm feeds to reach and maintain the target setting.

Nutrient Heaters

Code Price Qty
Heavy Duty Hydor Nutrient Heater 50 Watt 0179 Heavy Duty Hydor Nutrient Heater 50 Watt
Heavy Duty Hydor Nutrient Heater 150 Watt 0224 Heavy Duty Hydor Nutrient Heater 150 Watt
Heavy Duty Hydor Nutrient Heater 300 Watt 0225 Heavy Duty Hydor Nutrient Heater 300 Watt


Are you correctly storing nutrients and boosters?

Before you’ve even managed to create a nutrient solution, there is a risk of damaging particular products due to poor storage. PK boosters are a classic example, whereby precipitation occurs and the contents become unusable due to overly cold. Although the effect can be reversed, you should really try and avoid it – keep nutrients and additives out of direct sunlight, in a cool dark place, where temperatures sit between 10oC and 19oC. Find out more here.

Precipitated nutrients After working through this Winter Health Check for your grow room, you should be in a great position to push on and maximise plant performance throughout the chillier months of the year. Don’t let the bitter cold bully you!

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<![CDATA[Fed up of hand-watering plants? Or tired of removing the run-off? Then check out RhizoSystems!]]> Mon, 12 Jan 2015 13:00:19 +0000 Although you'll find 24 different RhizoSystems available at present, this large number of products can be split into two distinct groups based on the performed tasks. Drain Only RhizoSystems solely deal with the issue of collecting and removing run-off from below RhizoPots whereas Drip & Drain RhizoSystems also allow you to automate feeds using an advanced network of drippers. Both of these systems are worth exploring separately...


RhizoSystem Drain Only


- Designed to remove the run-off from underneath RhizoPots

- Fast, efficient and tidy

- Can be used if you hand water plants or with an existing drip system

- Customisable systems of up to 72 pots

Drain Only System

Removing run-off - The RhizoStands

One of the key elements of the RhizoSystem is the RhizoStand. It has been moulded to comfortably accommodate a variety of sizes of RhizoPot, and ensures that run-off quickly leaves the area immediately surrounding the roots via a series of channels all sloped down towards a single outlet. At this point, the RhizoSystem Brain Controller can draw up the excess nutrient solution through the attached 25mm Iceline Pipework.

RhizoStand There are currently two variants of the RhizoStand, which include the following:

- STANDARD: suits all sizes of RhizoPot up to the 16 Litre model

- XL: suits all sizes of RhizoPot up to the 39 Litre model


Removing run-off - 25mm Iceline Pipework

The 25mm Iceline pipework has been purposely selected to remove the run-off for the following reasons:

- Guarantees fast removal

- Much quicker than using the 13mm pipework found on competitor products

- Much less likely to become blocked or back up

- Stands can be spaced apart and positioned to suit the shape of your room (just make sure the pipework is pulled tight)

Iceline pipework Removing run-off - The RhizoSystem Brain Controller

All run-off is drawn through the pipework into the RhizoSystem Brain Controller. Features include:

- 6 inlets (using 25mm fittings) for creating 6 lines of pots (maximum recommended run of 12 pots per line)

- Maxi-Jet 1000 Pump

- Magnetic Float Switch (reliable IWS components)

- Time delay to ensure minimal run-off is left in the RhizoSystem Brain
RhizoSystem Brain

Removing run-off - The final destination

From the RhizoSystem Brain Controller, you need to work out where you'd like the run-off to be directed - most people either point it towards a drain or a waste bucket. Here are a few things to consider when making your decision:

- The run-off is carried out of the RhizoSystem Brain Controller using 13mm Iceline Pipework

- The kit contains a non-return valve to stop the Maxi-Jet Pump from becoming air-locked

- If you have a drain in your room and can allow gravity to carry the water, then you just need RhizoStands and pipework

Waste Bucket RhizoSystem Drip & Drain


- Efficient run-off collection network combined with pressure compensated drip irrigation system

- Utilises Iceline pipework throughout

- Systems available up to 48 pots, all completely customisable

Drip and Drain System Irrigation System

- Easy to install Iceline pipework

- No need for hot water

- 360o Pressure Compensated Drip Stakes equally distribute nutrient solution across pots and media

- Standard RhizoStands use 1 dripper per pot, XL RhizoStands use 2 drippers per pot

- Includes convenient 19mm 8 outlet manifolds (so you don't have to pierce the pipework to connect drip lines)

- Inline tap installed on the end of each line for periodically flushing the line

360 Drippers

8 outlet manifold Reservoir

A complete reservoir assembly is supplied with all Drip & Drain kits. This includes the following items:

- a high-pressure pump

- a good quality inline filter

- all the necessary components to get it up and running.


If you want to stop your plants from spending time sat in run-off after feeds (which often leads to oversaturation and root rot) then there really is nothing else that can come close to the effectiveness of a RhizoSystem. Every component in these kits has been carefully picked out based on quality and ease-of-use, yet the pricing doesn't exclude anyone at all. The option of adding irrigation equipment even makes it possible to create a fully automated nutrient distribution and drainage system, totally consigning hand-watering to the past! A fantastic set of additions to the RhizoPot family!      RhizoSystem

http://www.growell.co.uk/blog/wp-content/uploads/2015/01/cover-web-150x150.jpg <![CDATA[Fed up of hand-watering plants? Or tired of removing the run-off? Then check out RhizoSystems!]]>
<![CDATA[5 Biggest Mistakes Made By Growers Over The Holidays]]> Tue, 16 Dec 2014 11:58:55 +0000 1. Forgetting to feed your plantsHand-watering

It might seem obvious, but failing to find the time to feed your plants can have catastrophic effects on their continued development. In the short term they are prevented from accessing the vital nutrients and water required for further growth, over a longer duration all the good work you’ve done up till now will start to be reversed. Plants become stressed if held for too long without sufficient nutrient, sometimes to the point where root cells actually collapse. When this happens it leaves the door open to far more serious problems such as Pythium.


Such issues are easier to counter in active hydroponics systems where a nutrient top up prior to the festive period can help ensure that the plants get their much needed nutrients.


For anyone hand-watering plants in pots, maintaining a regular feeding schedule is imperative. Fortunately if you foresee time away from your grow room, there is a solution! Installing a drip irrigation system will provide peace of mind and allow your plants to be regularly fed. These are simple to set up, but we’d recommend doing so in advance to make sure you get the correct timings and durations of feeds (you don’t want plants sat in water from too much feed).

Code Price Qty
GroWell Holiday Watering Kit - 12 Plant 1547 GroWell Holiday Watering Kit - 12 Plant


2. Leaving your nutrients in a cold environment

Precipitated nutrientsStoring bottles of nutrients and boosters in an area exposed to cold temperatures tends to cause precipitation, whereby the elements that make up a product are no longer incorporated in the liquid. Sure-fire signs of this effect include the appearance of crystals on the surface of the solution and a rattling sound if the bottle is shaken. Problems occur when you try to add the nutrient/booster to your main solution because the key elements will not be accessible to the plants. The simple remedy is to keep your nutrients somewhere with a more stable temperature, perhaps away from the grow room.


Find out more about precipitation by reading our article "Protect your nutrients and boosters from the cold" - just click here!


The same principle applies to nutrients that have been premixed but are kept outside of the grow room (e.g. when it is in an attic or loft). Adding cold nutrients to your system can shock plants and stop them from performing to the usual standard – overcome this issue by placing a nutrient heater in your reservoir.


3. Not having spares/running out of an important product

If you have a bulb or timer failure during the holidays, you may not be able to visit your local GroWell store and could therefore struggle to get a swift replacement. Likewise, a shortage of nutrients or an essential booster over this period of time may also prove costly. Simply stock up in advance and carry spares of bulbs, timers and other crucial grow room equipment.

Essential products We recommend keeping reserves of lamps and timers as a form of good practice, but it is even more important over the holidays when replacements are not always easily sourced.

Code Price Qty
250 Watt Sodium Grolux 0574 250 Watt Sodium Grolux
400 Watt Sodium Grolux 0152 400 Watt Sodium Grolux
600 Watt Sodium Grolux 0155 600 Watt Sodium Grolux
Heavy Duty Lighting Timer and Contactor 1925 Heavy Duty Lighting Timer and Contactor
24 hour Grasslin Mechanical Timer 0114 24 hour Grasslin Mechanical Timer


4. Not maintaining your temperatures

One of the main benefits of indoor gardening is that you are able to regulate the growing environment. If you don’t regularly monitor it, temperatures may fall outside of the optimum range – and a swing either way can cause damage to your plants. Overly cold conditions will see plants struggle to perform, but a really hot climate often proves to be a lot worse, leading to a loss of moisture and numerous related problems.

Target temperature Stabilising temperatures in advance reduces your likelihood of being caught out by a cold snap. Aim to establish suitable heating and extraction set ups to maintain the desired conditions. A quick check that everything is in working order will always provide peace of mind.

Code Price Qty
80 Watt KlimaHeat Tubular Grow Room Heater 0611 80 Watt KlimaHeat Tubular Grow Room Heater
800W Oil-Filled Grow Room Radiator 7675 800W Oil-Filled Grow Room Radiator
2.5kW Oil-Filled Grow Room Radiator 7676 2.5kW Oil-Filled Grow Room Radiator


5. Forgoing bug checks 

The process of checking for insects is easily overlooked, especially in winter, but since you are controlling your own growing environment, pests are unfortunately a year round problem. Therefore you must perform a thorough bug check if you are expecting to be away from the grow room for any period of time. Failure to do so could lead to an infestation taking hold in your absence – and a small one left unattended for a week will almost certainly decimate your plants by the time you return. Invest a few minutes to search your growing space, leaves, stems, etc. for insects and respond quickly and effectively to unpleasant discoveries in order to save the crop.

Code Price Qty
Active Eye Magnifier 0908 Active Eye Magnifier
Horti-Shield Yellow Sticky Insect Traps 1926 Horti-Shield Yellow Sticky Insect Traps
Protector Natural Insect Killer - 1 Litre Sprayer 0482 Protector Natural Insect Killer - 1 Litre Sprayer


Going through these steps prior to the holidays will help you to relax and enjoy the time off, putting you in a much better position to cope with any problems that might be encountered.

http://www.growell.co.uk/blog/wp-content/uploads/2014/12/Mistakes-150x150.jpg <![CDATA[5 Biggest Mistakes Made By Growers Over The Holidays]]>
<![CDATA[Beginners Guide To Mixing Hydroponics Nutrient Solutions]]> Tue, 14 Oct 2014 14:55:59 +0000 Quick note: if you're not sure why pH and CF levels are important in the context of nutrient solutions, check out the introductory articles 'A Beginners Guide To pH Management' and 'A Beginners Guide To CF Control'. Once you have got to grips with how different pH and CF readings affect your feeds, it’s time to learn how to concoct a good batch!



You will need a small number of essential items to get your feeds set up. These include the following:

1.) CF Truncheon – factory calibrated to provide accurate readings of your nutrient strength

2.) pH Pen - to measure the pH level and ensure it is in optimum range

3.) pH Down, Measuring Jug, Syringes – general pH adjusting equipment

4.) Bucket – to mix your solution in

5.) Nutrients and Boosters

Nutrient Equipment Mixing Nutrients for the Vegetative Cycle


Leave the water to stand

To begin with you need to leave the water standing in a bucket overnight. This allows the chlorine to dissipate and the water to reach room temperature, so you can produce accurate readings and ensure that cold nutrient solution is not added to your tank – which may otherwise cause some shock to your plants.

Code Price Qty
20 Litre Budget Black Bucket 0493 20 Litre Budget Black Bucket

Base readings

After the water has stood overnight, the next task is to get the base readings. These provide the foundation from which you build the nutrient solution – without them all other readings are useless. The base readings should be taken from the plain water that has been stood overnight.

Base readings Using a CF Truncheon and pH Meter, the readings for this water show as 6 for the CF (0.6 is the EC reading, you just multiply this by 10 to get the CF figure) and 7.2 for the pH, indicating that soft water nutrients are required. See the table below to work out which type of nutrients you should be using:

Base readingsMixing the solution

With the base readings gathered you can now begin to mix your solution. A good starting point is always the manufacturers feed chart and/or the instructions on the bottle. Many people develop their own preference for CF levels, but as a beginner you’d want to keep it simple and use existing guidelines. For the SHOGUN Samurai Hydro Grow Nutrients featured in this article, you'll want to refer to their very cool feed chart on the product page (attached as a PDF file under the main image).




In this instance the nutrient solution will be created for plants in week 3 of the vegetative stage, and the manufacturers feed chart indicates that you should aim to achieve a CF level of 15 to 20 (a base reading of 2 is given by them). Now it is vitally important that you account for the base reading of the feed chart and the base reading of your own water prior to selecting the actual CF range you intend to target.


Since SHOGUN have used a base reading of 2 as the basis for recommending the CF range of 15 to 20 and the base reading for this example was registered at 6, you need to add the difference of +4 to each end of the target CF range – changing it to sit between 19 and 24.

CF pH adjustments The manufacturer instructs you that 2-3ml of nutrient per litre of water will be enough to achieve the desired solution strength. Add the nutrient to the water in increments, checking regularly with the CF truncheon to ensure you do not go over the target CF. Here 20ml of part A and 20ml of part B was added to the solution in 10ml increments using a syringe.

Adding nutrients

Code Price Qty
Nutrient Measuring Syringe - 20mls 0615 Nutrient Measuring Syringe - 20mls


As soon as it has been well mixed, check your solution. At the moment you can see the reading is only 14 (1.4 is the EC reading, you just multiply this by 10 to get the CF figure).

CF Check Add more nutrients, this time in increments of 5ml until the CF reaches the target range.

Adding more nutrients A reading of 20 is registered (2.0 is the EC reading, you just multiply this by 10 to get the CF figure), which falls within the recommended range based on the base reading. With the nutrient at the right strength, now you need to make it accessible to the plant.

Target CF

Code Price Qty
Bluelab (NZH) Nutrient (cF) Truncheon 0121 Bluelab (NZH) Nutrient (cF) Truncheon




To put it simply, in order for your plants to access all of the elements the solution contains the pH level needs to sit within a certain range – typically between 5.5 and 6.5.


With the nutrients added to the water, the pH Meter indicate the pH level has risen to 7.5 so it must be lowered.

Initial pH reading To lower the pH you need to use pH Down. Always dilute this product in a litre jug of water, not only because it is safer to use, but also in order to gradually adjust the level.

pH adjustment The pH down proves to be very strong, so adding just a few drops to a litre of water will dramatically change the pH of the solution. From a base pH of 7.2 a few drops of pH down drops it to 2.6, illustrating how easily you could end up putting too much into the nutrient solution if applied neat.

Code Price Qty
pH Down - 250mls 0130 pH Down - 250mls


pH Down

By adding a diluted pH solution to the nutrient solution it is a lot easier to control. Gradually mix this with the main solution.

Code Price Qty
1 Litre Measuring Jug 1546 1 Litre Measuring Jug


pH solution

Keep pouring in the pH solution until the desired pH level has been reached – here you’re looking at a target of 5.8.

Target pH level That concludes the process of putting together a suitable feed for plants in the vegetative stage. Now the solution can be added to your growing system.

Code Price Qty
Accuread pH Meter 7520 Accuread pH Meter


Mixing Nutrients for the Flowering Cycle


For the flowering stage, you do exactly the same as above apart from one big difference – if you’re using a PK booster or any other additives, you ought to add these before introducing the base (bloom) nutrients.

Flowering equipment Once you have your base reading, the first thing to do is to add the flowering stimulant SHOGUN Sumo Boost and PK booster SHOGUN PK warrior 9/18.Adding boosters

Checking the CF shows it to have risen to 14 (1.4 is the EC reading, you just multiply this by 10 to get the CF figure) – an increase of 8 from the base reading – so you’re able to realise that if the boosters were added after the base nutrient this could lead to a very high strength nutrient solution aka over feeding.

Boosters CF Then gradually add the bloom nutrients to the solution until you hit the target CF.

Add bloom nutrients

In this case the figure is 22 (2.2 is the EC reading, you just multiply this by 10 to get the CF figure), again based on the manufacturers feed chart.

Bloom CF

With the nutrient solution at the required strength, the pH level should be adjusted again using the same method as before until it registers within the target area. Finally you’re ready to add it to the growing system.

http://www.growell.co.uk/blog/wp-content/uploads/2014/10/01-veg-equipment-web-150x150.jpg <![CDATA[Beginners Guide To Mixing Hydroponics Nutrient Solutions]]>
<![CDATA[Master the Art of Ventilation – Fan Sizing]]> Wed, 10 Sep 2014 17:22:04 +0000 Extractor Fan Calculation

Extracting air out of your grow room and introducing fresh supplies must be done if you want your plants to thrive in an indoor growing environment. Selecting the right size of fan ensures that you maximise the effectiveness of your ventilation efforts.

Fan size guide

First of all it is important to understand the role of the ‘active growing area’. This concerns the space covered by the grow lights, which will differ between systems depending on the output:

250w light set up

400w light set up

600w light set up

1000w light set up

Taking the volume (length x width x height) of the active growing area and multiplying it by 60 gives you the figure for one complete air exchange of the growing area per minute – universally regarded as the maximum ventilation rate required. Anything more can reduce temperatures, which obviously does some good during the summer, but may still end up causing problems with regards to humidity.


So when you’re working out what extractor fan to select, a good starting point is to find a unit that comes close to the result produced from the key calculation.

Fan calculation Example

Extra Large (XL) BudBox Grow Tent – 1.2m length x 1.2m width x 2.0m height


1.2 x 1.2 x 2 = 2.88m3

2.88 x 60 = 172.8m3/hour


At the moment a 100mm (4”) RVK100A1 fan seems suitable for this scenario with an air moving capacity of 175m3/hour. However, it does not consider the impact of attaching a carbon filter and ducting…


Carbon Filters, Accessories and Fan Efficiency

A carbon filter and ducting accessories will significantly reduce the speed of an extractor fan. The level of drop off depends on the fan motor, the type of carbon filter (pelletised carbon in Prima Klima products has been designed for air filtration – unlike those of competitors incorporating water filtration technology) and the ducting (the longer the length of ducting, the less efficient the ventilation system).


To factor in the expected fan speed reduction of around 25%, multiply the original calculation by 1.33.

Carbon filter and ducting Example

Extra Large (XL) BudBox Grow Tent – 1.2m length x 1.2m width x 2.0m height


1.2 x 1.2 x 2 = 2.88m3

2.88 x 60 = 172.8m3/hour

172.8 x 1.33 = 230m3/hour


With an air moving capacity of 225m3/hour, the slightly larger 125mm (5”) RVK125A1 is now better suited to the set up than the originally highlighted model.


Other factors to consider

In most cases the calculations above will be enough to identify the correct size of fan, but some people may also find consideration of the following points necessary:


Grow Room Location:

- Add 20% for a warm attic

- Minus 15% for a cool basement

- South facing rooms will tend to be hotter than north facing rooms – increase the size of fan and use a fan controller for exposed areas

Attic and basement Ventilation System Configuration:

- Add 20% for long ducting runs and/or multiple bends

- If incoming air is 25oC or above then the room will become hot irrespective of the ventilation – an OptiClimate System or Air Conditioning Unit is the only solution

OptiClimate System Grow Room Lighting:

- Minus 25-30% for air cooled lighting

DARKSTAR reflector

Intake Fan Calculation

On top of the fan required to extract stale air away from your growing area, you typically tend to need another one to regularly bring in fresh supplies.


Achieving negative pressure whilst ventilating your grow room is critical – otherwise unfiltered air will be sent out of the vents and ports (if you’re using a grow tent, this may even start to inflate!) To create desirable conditions, an intake fan should be 15-20% less powerful than an extractor fan.

Intake fan calculation Example

Extra Large (XL) BudBox Grow Tent – 1.2m length x 1.2m width x 2.0m height


Extractor fan = 125mm (5”) RVK125A1 (225m3/hour)


(225 x 0.75) x 0.85 = 145m3/hour


Based on this calculation, the 100mm (4”) RVK100A1 (175m3/hour) most closely matches the target requirements for the intake fan.


Alternatively, you may be in a position to use one or more intake vents instead of a fan…


Intake Vent Calculations

If you’ve got a smaller grow room with only one grow light (up to 600W), you can often skip on the intake fan and introduce satisfactory amounts of fresh air via a series of vents.

Grow tent vent For every 1000m3/hour of airflow extracted, 0.09m2 of fresh air must be allowed in.


0.09m2 (900cm2) = 3 x 200mm circular holes


Grilles are often used on vents – these have free air space of approximately 60%



A 200mm x 200mm square grille = 0.04m2


60% of 0.04 = 0.024 free air space on the grille.


For airflow – 200mm x 200mm grille = (0.024/0.09) x 1000

= 267m3/hour


Therefore 4 x 200mm grilles would be needed for 1000m3/hour extraction.


We hope you have found this guide easy to use. Please feel free to leave comments!

http://www.growell.co.uk/blog/wp-content/uploads/2014/09/fansize-cover-web-132x150.jpg <![CDATA[Master the Art of Ventilation – Fan Sizing]]>
<![CDATA[New to Hydroponics and Indoor Gardening?]]> Thu, 07 Aug 2014 13:00:25 +0000 Everybody arrives here at different stages in terms of their gardening ability – from ‘never grown anything before’ to ‘allotment king’ – so we intend to try and provide a guide that covers all of the bases. Rather than reinvent the wheel though, the plan is to offer up concise answers to frequently asked questions alongside overviews of products and practices and then link to existing articles in the blog for more comprehensive demonstrations. That way, if you need help on a certain aspect of growing you’ll have less content to sift through!


Information is structured to flow logically, beginning with the meaning and principles of hydroponics, then moving on to an exploration of what you can grow as well as a look at the key products and processes for setting up, before finally taking a start-to-finish tour of the plant growing cycle. To give you a complete overview, we touch upon all of the following areas:

 Hydroponics system

1. A really quick introduction to hydroponics and indoor gardening

1.1 What is hydroponics?

1.2 Is growing indoors the same as growing outdoors?

1.3 Can I grow indoors with soil?

1.4 Which growing medium should I choose to use?

1.5 Should I be cautious of anything in particular?


2. Grow what you want, when you want!

2.1 What plants do you recommend for growing indoors?

2.2 Where is the best place to find out more about the plants I want to grow?

First grow room


3. Location, Location, Location!

3.1 How much space do I need to grow indoors?

3.2 Is there a minimum suitable height?

3.3 What temperatures and humidity will my plants thrive in?

3.4 What else do I need to take into account?


4. Setting up a grow room

4.1 What are the main things I need?

4.2 Why should I use a grow tent?

4.3 Why do I need a ventilation system?

4.4 How do I create a lighting system?

4.5 What is the best growing system for me?

4.6 Are there any other items of equipment I should know about?

Nutrient solutions


5. Feeding your plants

5.1 How do I feed plants in a hydroponics set up?

5.2 Have I got to feed soil-based plants or are there nutrients in the media?

5.3 What do plants growing in coco need?

5.4 How often should I feed my plants?

5.5 What additives shall I give my plants and when is it the best time to do so?

5.6 Are there any guides to follow for mixing nutrient solutions?


6. Ready, steady, grow!

Strong plant

6.1 Is it easy to get some plants started off?

6.2 Should I do anything now that I can see signs of initial root development?

6.3 How do you move your plants into a main system without upsetting them?

6.4 What is necessary to accelerate and prolong plant growth?

6.5 How can I get my plants to start developing fruits?

6.6 When is it the right time to start my harvest?

6.7 Is it too late to try and save the genetics of my plants at the end of a crop?

6.8 What should I do if bugs or disease threaten to ruin my crop?


7. Gearing up to go again!

7.1 What do I need to clean after a crop?

7.2 How should I store my nutrients and boosters?

7.3 When is the right time to replace equipment?


8. A final note


Honestly, getting to grips with the basics of hydroponics and indoor gardening takes minimal time and effort – in fact, finding your way to a good source of information is arguably the hardest part! And fortunately, you’ve arrived at one!


Now, where to begin? How about with…


1. A really quick introduction to hydroponics and indoor gardening


1.1 What is hydroponics?

By reaching this page it’s fair to say that you may already have a rough idea about what ‘hydroponics’ means. Nevertheless, just to clarify in a short and simple manner, the term basically refers to the method of using water instead of soil to deliver nutrients to plants.


How the water is effectively made to deliver the nutrients to the plants can differ depending on the system design a grower selects (e.g. a bubbler/DWC system ‘bubbles’ the water whereas a dripper-based system ‘drips’ it), and each different type possesses unique benefits compared against the next – for more details see 4.5 What is the best growing system for me?

Hydroponics systems In order for the plants to properly uptake the nutrients, you must mix the feed concentrate correctly with the water. This involves checking and adjusting the pH level and conductivity of the solution, which might sound quite daunting but actually takes just a few minutes – for more details see 5.1 How do I feed plants in a hydroponics set up?


1.2 Is growing indoors the same as growing outdoors?

Yes and no. A lot of the same principles apply but you have much closer control of your plants in an indoor environment. Being able to precisely tailor grow room conditions makes it possible to nurture species only normally found away from the UK and to produce plants all year round. Creating the perfect setting for plants to thrive in also encourages them to completely fulfill their potential and produce bucket-loads of high quality fruits. Not bad, huh?


1.3 Can I grow indoors with soil?

Certainly. We are strong advocates of hydroponics, yet the traditional method of growing plants in soil should never be ignored. It is rather messy and yields (total fruit production) tend to fall well below ‘soil-less’ alternatives, but on the other hand it is incredibly easy to do and promises exceptional results regarding looks, tastes and aromas.

Using soil indoors

Sitting between soil and hydroponics you’ve got coco too. This organic growing media gives you the best of both worlds (high quality, big yields) and appears strangely familiar – feeling and looking a lot like soil.


1.4 Which growing medium should I choose to use?      

Depends on your goals and confidence. Soil often suits beginners because it’s quite simple to manage, whereas organic soil will please the purists and really hit the mark in terms of quality of fruits.


Getting Your Hands Dirty – Growing In Soil


Growing With Organics


Coco represents a great stepping-stone for soil growers who want to work up towards hydroponics or for those demanding quality and quantity in equal measure.


Hydro-Organics: The Coco Alternative

Coco growing media

Just like hydroponics, the coco approach requires pH and CF tweaks to nutrient solutions – not that this should deter you from either option.


Hydroponics is very clean and efficient, so much so that crop times are often considerably reduced! The main benefit concerns yields, which will go through the roof and overshadow what can be achieved with other methods!


1.5 Should I be cautious of anything in particular?

The only things that can stop you from achieving great results in an adequately sized grow room (for more details on dimensions see section 3) are extreme temperatures, bugs and disease. With a suitable ventilation system (see 4.3 Why do I need a ventilation system?), pest management strategy and plant health maintenance regime (see 6.8 What should I do if bugs or disease threaten to ruin my crop?) there is nothing to worry about!

Grow room hazards 2. Grow what you want, when you want!


2.1 What plants do you recommend for growing indoors?

If you’ve made your mind up and want to grow indoors, the chances are there is already a particular fruit or vegetable influencing the decision – be it lettuce, tomatoes, peppers, strawberries or something equally as appealing. Indeed, you can even produce bananas!


Top Banana!

Banana tree

Most plants that you can think of will really flourish inside a specially created grow room, but each one inevitably has very specific requirements with regards to feed strengths, feed frequencies, room temperature, room humidity, etc.


In terms of a recommended starting point, chilli plants are a favourite of ours at GroWell.


Question Time: Growing Chillies


The Twilight variety stands out, proving to be relatively straightforward to grow irrespective of your level of experience. For a ‘start-to-finish’ grow diary based around this plant that’s aimed at beginners, have a look at the following link:


Twilight Chillies Grow Diary – Hydroponics and Soil

Twilight Chillies 2.2 Where is the best place to find out more about the plants I want to grow?

It’s important to do your research into the needs of the plants you would like to grow. For some help and guidance, talk to our tech team on the ‘Chat with us’ tool (bottom right of the page) or call 0845 345 5176. Check out a few of the examples below that are taken from the blog:


Friars Hat Chillies (aka Bishops Hat and Barlett’s Bonnet)


Masdevallia Constricta Orchids


Triple White Metel Brugmansia (aka Angel’s Trumpet)


3. Location, Location, Location!


3.1 How much space do I need to grow indoors?

A spare room, empty garage or vacant loft will be ideal. Then again, you can use the corner of a room or even a closet if space is at a premium! Look for an available area of at least 75cm x 75cm.

Garage, loft or spare room 3.2 Is there a minimum suitable height?

Height represents the biggest issue – you could get away with 160cm from top to bottom but we’d suggest no less than 180cm to allow for a decent amount of foliage. Be aware that grow lights generate heat so you will want to establish some form of a gap between them and your plants to avoid burning the canopy.


3.3 What temperatures and humidity will my plants thrive in?

Although it does depend on the type of plant being grown, most people’s target room temperature tends to range from 24oC to 28oC. At certain times the selected setting will be a challenge to maintain (in super hot summers and freezing cold winters) but there are plenty of tips and tricks to overcome any potential problems.


How To Survive Soaring Temperatures This Summer


Winter Is Coming…

Daytime temperature The close relationship involving temperature and humidity means that one should never be talked about without reference to the other. For a grow room kept at 24oC-28oC, the recommended relative humidity is 50-70%. However, a greater understanding of these two important factors is required if you want to fully optimise your grow room.


Harnessing The Power Of Humidity


Temperature, Relative Humidity and Vapour Pressure Deficit

Target humidity If you’re going to grow plants hydroponically, you must also remember to take care of nutrient solution temperatures. In the root environment, the most favourable conditions sit between 18oC-20oC. Again, you can find equipment to help ensure your target is reached during heat waves and big freezes.


Keep Your Nutrient Solutions Cool This Summer


Everything You Need To Know About Nutrient Heaters!


Cold War Heroes – Nutrient Heaters

Target Temperature 3.4 What else do I need to take into account?

Ensuring that fresh air is able to reach your plants should be high up on your agenda – at the very least you should make the most of the passive intake holes featured on a grow tent. For the best outcome though, we suggest installing an intake fan and drawing air in from a different area to the one housing your plants.


You must also consider the implications of the size of the preferred growing system, both in terms of ground covered and height (e.g. NFT Systems are low to the floor whereas a Wilma System is taller), and whether suitable access to your plants can be gained.


4. Setting up a grow room


4.1 What are the main things I need?

Once you’ve identified a decent location for your plants, it’s time to work out what equipment to use. The main hardware will include a ventilation system, a lighting system and a growing system. We also recommend installing a grow tent rather than just attaching reflective sheeting to your walls.


Building Your First Grow Room


Setting Up A Grow Room

Light, fan, filter and tent 4.2 Why should I use a grow tent?

You can create a perfectly suitable grow area for raising plants with as little as a roll of plastic sheeting. However, a grow tent will help you improve your overall control of the environment, cleanliness and bug prevention, conveniently separating plants off from the immediate surroundings. Quality designs from the likes of BudBox feature durable tent canopies and super sturdy frame pieces that are guaranteed to stand up to numerous crops, therefore representing a very worthwhile long-term investment.


How To Make The Most Of Your Grow Tent

BudBox Grow Tent 4.3 Why do I need a ventilation system?

After constructing your grow tent we recommend focusing on the ventilation system. The extraction element of it usually hangs towards the back of the tent – an otherwise difficult section to reach with a light already suspended – and comprises of a fan, carbon filter and all the necessary ducting parts. When the equipment is set up, you can reliably and regularly replace the air in your grow room to keep the surrounding environment fresh and clean. An additional fan for intake purposes also proves worthwhile for use with 150mm extractor fans and above sizes, whilst air circulators do a great job at keeping air continuously on the move.


Master The Art Of Ventilation – How Airflow Affects Your Plants


Master The Art Of Ventilation – What Equipment Do You Need?


Master The Art Of Ventilation – Setting Up A Complete System

Fan and filter 4.4 How do I create a lighting system?

To set up a safe and effective lighting system we recommend equipping yourself with a reflector, lamp, ballast, timer, contactor and light hangers.


You must carefully consider the power rating of your lighting system – 250 Watt, 400 Watt, 600 Watt or 1000 Watt. More light typically equates to more growth but you have to take into account the size and height of the growing area. On the same note, the reflector/lamp should be carefully positioned to ensure plants receive the optimum amount of light whilst not suffering from overexposure to heat.


A Lesson In Lamps: Model Specs, Coverage Areas, Top Tips And More


A Lesson In Lamps: Hanging Heights

Grow Light A very effective way of reducing the heat that reaches plants via your lamp(s) is to employ an air-cooled lighting system. These feature special reflectors that connect up to a fan and ducting to allow for air to be blown across the lamp in an attempt to keep it/them and the surrounding area cool.


Close Encounters – Air Cooled Lighting Systems

Air Cooled Lighting Reflectors are designed to guide the light produced by a lamp down towards your plants. The better the design, the more of the light that will reach the all-important areas.


Flexible Reflectors – Adjust-A-Wing Avenger vs Adjust-A-Wing Enforcer


Don’t Waste A Watt – Effective Reflector Designs


Over time the light output of lamps and the reflectivity of reflectors will naturally decline due to usage – be aware of when you need to replace them.


How Much Yield Are Your Lights Losing You?


In some instances where you can accommodate multiple lighting systems, it makes better sense to set up a LightRail. This basically enables one light to cover the area that would otherwise need to be occupied by two, giving you a whole host of plus points.


Lights, Rail, Action!

LightRail Light Mover 4.5 What is the best growing system?

All of our growing systems are excellent – we wouldn’t sell them otherwise!


If you’ve decided to go down the hydroponics route, you’ll soon discover that there’s a wide range of distinctive soil-less growing styles, each with their own specific systems. But how exactly do they differ? It essentially comes down to the application and delivery of the nutrient solution. For example, Flood and Drain Systems feed plants by periodically immersing the roots in a mixture of water and nutrients before then gradually draining the whole lot away, whereas Bubbler/DWC Systems require the rootzone to be constantly submerged in an aerated solution. The consequence of these different designs is unique sets of benefits, so take the time to review our growing systems pages and blog articles (links below) and carefully think about what appeals to you.


Choosing A Growing System – A Buyers Guide For The Beginner


Nutrient Film Technique (NFT) Hydroponics Systems


Bubbler/Deep Water Culture (DWC) Hydroponics Systems


Flood And Drain Hydroponics Systems

IWS System Soil and coco growers are more restricted in terms of suitable growing systems. We highly recommend Rhizo-Pots to both sets of people, since these innovative products facilitate the hugely advantageous process of air-pruning to eliminate root circling and push new root growth.


Introducing Rhizo-Pots!


The Stress Factor: Air Pruning For Improved Roots

Rhizo-pots Aside from Rhizo-Pots, users of soil and coco also have the options of plastic round and square pots. To automate feeds, the latter can be put in a gravity-fed system like the AutoPot, a dripper-based system like the Wilma or alternatively made part of a DIY irrigation set up.


Producing Awesome Chillies With An AutoPot System


An Introduction To Irrigation


Automating Feeds Using DIY Drip Irrigation Components


Setting Up An Irrigation System Using A GroWell Holiday Watering Kit

AutoPot System 4.6 Are there any other items of equipment I should know about?

Given the huge number of gardening products that are currently available, it is not unusual to accidently scan over some of the more ‘small but brilliant’ components that are often very useful in the grow room. Whilst a lack of these items won’t prevent you from growing, having them in place can work wonders!


Grow Room Essentials


All The Small Things


5. Feeding your plants


5.1 How do I feed plants in a hydroponics set up?

By creating nutrient solutions. You basically just fill a bucket or tank with water and let it stand for 24 hours (to de-chlorinate) and then mix in an appropriate amount of base nutrient, which contains key elements for growth. Adding stimulants and boosters will up the amount of certain elements, leading to all sorts of different benefits. You also need to appreciate how pH levels have an impact on the availability of nutrients, whilst conductivity (CF/EC) indicates nutrient strength and the suitability of feeds for plants.


What’s The Best Nutrient For You?


A Beginner’s Guide To pH Management


A Beginner’s Guide To CF Control

Nutrient solutions 5.2 Have I got to feed soil-based plants or are there nutrients in the media?

Some soils feature enough nutrient content to get you through propagation (BioBizz Light Mix) and the early vegetative growth stages (BioBizz All-Mix), so you only need to give plants water at these times. Later ‘grow’ and ‘bloom’ feeds are still required – just like for hydroponics. The only major difference between hydroponics and soil feeds is that the latter doesn’t require pH and CF checks/adjustments.


5.3 What do plants growing in coco need?

Coco closely mirrors hydroponics when it comes to feeds – you can even use the same additives! However, coco specific formulations will deliver the best results for base nutrients.


Growing In Coco – Getting The Basics Right!

Coco nutrients 5.4 How often should I feed my plants?

In anything other than standalone pots, your plants will automatically be fed nutrient solution. We recommend completely changing nutrient solutions as opposed to regular top ups. If you can only do the latter more often than not, make sure it is all replaced at least once every 1 or 2 weeks, with ¼ strength feeds between changes.


Changing Nutrients


For plants in standalone pots of soil or coco, conduct feeds with a watering can, bucket or large measuring jug. Afterwards, lift each plant to get a sense of how heavy they feel when “full”. Then every now and again check the weight to see if your plants have been drinking. The “lighter” they feel, the more likely they’ll need a feed sooner rather than later.


5.5 What additives shall I give my plants and when is it the best time to do so?

If you are growing plants in soil, stick to soil-specific additives (not that this is a limitation, there are loads to choose from!)


Hydroponics and coco growers have got even more to play with than their soil counterparts due to the extra degree of control on offer. A wide array of stimulants now exist, letting you enhance almost every aspect of a plant for the end gain of bigger yields!


Top Tips For Boosting Your Yields – Hydroponics Additives And Stimulants

Adding stimulants 5.6 Are there any guides to follow for mixing nutrient solutions?

Yes. You’ll find feed charts for all of the big nutrient ranges on the relevant product pages of the GroWell website. They are in the ‘Related Product Information’ section (underneath the main image), as print-friendly PDF files.


Vita Link Max


BioBizz Grow and Bloom


Canna Coco Professional


6. Ready, steady, grow!


6.1 Is it easy to get some plants started off?

There are two methods for beginning a new crop – either you take cuttings or start off seeds. In both cases, the main objective is the production of roots. To do this you will need a propagator, a scalpel, rooting gel, measuring cup, fluorescent lighting, a sprayer, propagating media (products exist for hydroponics, coco, soil and organics) and cutting/seedling feed.


Starting from seeds has its advantages if you’ve not got a mother plant or are completely new to gardening.


Starting Off Seeds

Starting off seeds Taking cuttings gives you the ability to clone an existing plant and continue the genetics – something every grower should want to do with a top performer.  After all, this often leads to a replication of the original success!


Taking The Perfect Cuttings

Taking cuttings When you are competent at taking cuttings, you ought to try out different types of equipment and products in an attempt to reduce rooting times and quicken up the overall grow cycle. For example, the propagator you choose to use can make a big impact.


The Race To Root Cuttings: The Propagator Challenge


6.2 What needs to happen once I can see signs of root development?

Roots will emerge from your propagating media 10 to 20 days after the seeds/cuttings have been started off. The plants are now rooted and ready for the next stage – transplanting. Here you aim to provide the plants with a more stable base ready for when they take up their final position in a main system or pot.


Hydroponics Transplanting


Soil Transplanting


Back To Basics: Transplanting In Soil

Transplanting in soil 6.3 How do you move your plants into a main system without upsetting them?

First it’s important to understand when to act. For adopters of hydroponics, the sight of roots pushing out of the bottom of the transplanting cube tells you the moment has arrived. If you’re intending to move a plant growing in coco or soil from a small pot to a large pot and can’t see the roots, you must make a judgment call based on the development of the foliage.


Introducing Plants To A Main System

Moving into main system 6.4 What is necessary to accelerate and prolong plant growth?

When you move your plants into the main system they will be at the vegetative growth stage of the lifecycle. Keeping the focus on root and foliage development encourages them to become bigger and stronger, improving the efficiency of internal functions and supporting the addition of numerous new flowering sites. An 18-hour lights on/6-hour lights off daily program and “grow” nutrients/stimulants are required to promote vegetative growth and prevent flowers from forming too soon.


Sometimes you’ll want to extend the vegetative cycle, maybe because of slower than expected growth or an overriding passion to produce massive plants. On top of closely managing your lights and feeds, there are extra tactics you can employ.


Extending The Vegetative Cycle

Pinching out flowers 6.5 How can I get my plants to start developing fruits?

Understanding how and when to get plants to switch to the flowering stage is a mightily important skill. All your work will have been for what follows next, as the precious fruits begin to appear! Again the transition from vegetative growth to flowering largely depends on the light and nutrients supplied to plants. The light cycle changes to 12-hour lights on/12-hour lights off and for feeds you swap out the ‘grow’ nutrient for a ‘bloom’ one. Easy!


Switching To The Flowering Stage


Being able to properly prune your plants will encourage fruits to ripen at a faster rate.


Pruning Plants For Improved Ripening

Pruning plants 6.6 When is it the right time to start my harvest?

Having a harvest strategy might seem a little unusual but there are a few different ways to collect the fruits that pop up on your plants.


Enjoying The Fruits Of Your Labour

Harvesting fruits 6.7 Is it too late to try and save the genetics of my plants at the end of a crop?

Missing the opportunity to take cuttings earlier on in the grow cycle doesn’t necessarily mean you’ve completely lost the chance of saving the genetics of a plant. There are several options including overwintering, seed stratification and taking cuttings during flowering.


Saving Plant Genetics: Overwintering


Saving Plant Genetics: Stratification


Saving Plant Genetics: Taking Cuttings


Saving Plant Genetics Revisited

Taking seeds 6.8 What should I do if bugs or disease threaten to ruin my crop?

Don’t panic! Just put into place a pest management strategy and plant health maintenance regime! This involves regularly checking your plants and using products for prevention, identification and treatment.


A Bug’s Life


The Definitive Guide To Dealing With Spider Mites


Attack Of The Aphids


The Neem Tree And Its Impact On Indoor Gardening


Got Rotting Roots? Pythium: An In-depth Analysis

Predators sachets

7. Gearing up to go again!


7.1 What do I need to clean after a crop?

Everything. Thoroughly. The area you intend to grow plants in must be kept clean before, during and after a crop, otherwise pests and disease will soon run riot. Sweep the floor and walls, hoover up as much dust and dirt as possible and spray the entire room with a reliable cleaning product like RoomClean or Oxy-Plus. Running the latter through a hydroponics system also works to kill all harmful bacteria and pathogens – we recommend adding it to water at 10mls per litre.

Clean room

7.2 Where should I store my nutrients and boosters?

Ideally, nutrients and boosters need to be stored somewhere out of direct light and with a stable temperature. Certain bottled products require extra care due to the threat of precipitation, but obviously nothing too strenuous!


Protect Your Nutrients And Boosters From The Cold


7.3 When is the right time to replace equipment?

General wear and tear will lead to a gradual decline in the effectiveness of most growing products. Pay particularly close attention to your grow lamps and reflectors, since these items have a huge impact on yields and start to deteriorate after the first crop.


How Much Yield Are Your Lights Losing You


8. A final note


Growing plants is very much a case of trial and error, with every crop providing valuable experience and an opportunity to learn something new. Enjoy the process, recording what works well and what could have gone better. Very few people get the perfect mix of products and processes first time out, so expect some set backs as well as pleasant surprises along the way. Apply a little bit of patience and soon enough the results will come!

Chilli plant We have friendly experts on hand at GroWell to provide advice and help you with any problems encountered. You can reach us via the website chat feature, by leaving a message towards the bottom of a blog article, through our facebook page, at any of our shops and from calling the customer careline – which is 0845 345 5176


Happy growing!

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<![CDATA[Digital Ballasts vs Magnetic Ballasts]]> Thu, 07 Aug 2014 10:11:33 +0000 What is a ballast?

A ballast for a high intensity grow light, such as high pressure sodium (HPS) or metal halide (MH), is an appliance that is needed to regulate the output voltage going to the lamp in order to start up the grow light and keep it running. Due to the properties of HPS and MH lamps, the ballasts are used to limit the current in order to maintain lamp operation.

Exolux Pro Ballast

Digital Ballasts vs Magnetic Ballasts


Size and Weight

The first and most obvious differences relate to size and weight – magnetic ballasts are larger and heavier than digital ballasts. Why? Well, magnetic ballasts use what’s known as a ‘choke’ to regulate the lamp voltage, made from a steel core wrapped with metal wire. This steel core is usually laminated steel plates and the wire coiling around it can be copper or aluminium, which combine to create an electromagnetic field that regulates the output voltage.

Inside a magnetic ballast

On the other hand, a digital ballast employs solid state circuitry to transform and regulate the voltage, representing a fraction of the size and weight and requiring far less raw material.

Inside a digital ballastElectrical Efficiency

Digital ballasts are far more efficient than their magnetic counterparts. Exactly how much of a difference you can expect to see really does depend on the units being compared, but typically it is 3-4%. Although this may not sound like much, when you’ve got multiple grow lights the combined saving will help to significantly cut your energy bills.


Heat Output

Due to the nature of the electrical flow through the core and coils of the choke featured in a magnetic ballast, heat will inevitably be produced. This emission of energy is an unwanted by-product and clearly demonstrates a loss in electrical efficiency. Digital ballasts also generate heat through the solid state circuitry, but much less by comparison. The internal components are actually encased in plastic to help deal with the issue.

Protected components Noise

Magnetic ballasts create a low level hum, usually because of vibrations in the coil windings. As these particular units age they progressively get louder and louder due to a slight loosening up of the coils, and this trend also tends to make them marginally less efficient too. Now noise is not a bother to some people, but it can get quite annoying when you want to run a quiet grow room. Fortunately digital ballasts are completely silent during operation, with no humming or buzzing whatsoever!


Consistency Of Light Output

The electrical supply across the UK varies considerably, with the voltage ranging from 220-258 volts (V) depending on your location. A magnetic ballast operates efficiently at 230-240V – any lower an incoming voltage causes the ballast to under-perform, any higher an incoming voltage and the ballast will use more power. Basically, a magnetic ballast controls the voltage to the lamp but it is dictated by the voltage received. Therefore, a variation in the mains voltage means a variation in electrical usage by the magnetic ballast and light output from the lamp, which ultimately affects plant growth and yield.

Light output However, digital ballasts have the ability to transform the incoming voltage up or down to 240V, ensuring you get a consistent light output regardless of the supply voltage variations.


Here are some examples to further explain:


Grower A lives in a standard voltage area of 240V and opts for a 600W magnetic ballast, which uses an average of 650W to drive the HPS lamp (this is quite normal, a 600W ballast typically uses between 640-660W).


Grower B sets up the same lighting equipment but has a supply voltage of 235V. This causes the ballast to underperform, only drawing 618W at the wall and delivering less light to the plants.


Grower C also works with the same equipment but has a supply voltage of 245V. This causes the ballast to go into overdrive, using an increased 685W at the wall and over powering the lamp so that it creates more light and heat.


If all these growers chose to run digital ballasts like the 600 Watt Exolux Pro (pictured below) with their HPS lighting kits they would each use exactly the same amount of electricity and deliver exactly the same amount of light, if not more, to their plants!

Side view of ballast

Code Price Qty
Exolux Pro 600 Watt Dimmable Digital Ballast 1991 Exolux Pro 600 Watt Dimmable Digital Ballast


To make things a little more complicated, voltage can fluctuate by as much as 10-15V depending on the time of day (due to the demand on the grid) and by the amount of electricity you are drawing on a circuit at your property. So every time an extra magnetic ballast is added to the electrical circuit that powers your grow room, the voltage reduces, consequently decreasing the light output of all your lights! Since digital ballasts can regulate the supply voltage, all of your lights perform the same regardless of the number of units. This leads to huge power saving benefits, as well as increased light output in large grow rooms.


NOTE: due to the energy savings and lower temperatures, we always recommend running your grow lights through the night and having them off in the day.

Nighttime temperature High Frequency Lighting

A magnetic ballast is governed by the electrical frequency it receives from the main supply, which registers at 50Hz (essentially meaning it goes on and off 50 times per second). Such a frequency is fairly low, producing a ‘flickering’ sensation at the lamp – for evidence, try using a digital camera under a lamp driven by a magnetic ballast and you’ll quite clearly see the banding effect it causes.


Digital ballasts have the ability to regulate the output frequency and operate at much higher levels of 40,000-100,000 Hz, depending on the brand and model. This not only makes it easier to take pictures of your plants (!), it also excites the gases in the lamp more efficiently resulting in better light output and a longer lamp life.


Dimmable Lighting

One excellent feature of a digital ballast over a magnetic ballast is that the output can be adjusted. There’s the option of either using a manual dimmer switch, as found on the Exolux Pro Digital Ballast, or using advance controllers that automatically dim the light output, as featured on the Dimlux Expert Digital Lighting Systems when used in conjunction with the Dimlux Maxi Controller.

Dimlux and controller

Why would you want to dim the lights?


Firstly, during vegetative establishment when the plants are small they do not need a lot of light. In fact, providing intense light can be very stressful for the plants and often causes transplant shock. Bringing the plants on in the first week or so under less intense light will make it more comfortable for the plants, and enable them to quickly settle into their growing environment.


Secondly, during periods of high temperature where ventilation systems cannot keep up and temperatures rise above what plants are able to tolerate, you have the option of dimming your lights to help reduce the heat at the flick of a switch.

Dimmable Ballast

Alternatively, for users of Dimlux Expert Lighting and the Dimlux Maxi Controller, it’s actually possible to set an upper temperature limit so that the lights will dim automatically!

Dimlux Maxi Controller

Doesn’t really get much easier than that, right?

Room too hotLights are dimmed

Code Price Qty
600 Watt Dimlux Expert Series Complete Light System 7045 600 Watt Dimlux Expert Series Complete Light System
1000 Watt Dimlux Expert Series Complete Light System 7046 1000 Watt Dimlux Expert Series Complete Light System
Dimlux Maxi Controller 5301 Dimlux Maxi Controller
Dimlux Temperature Sensor - 10m Lead 5328 Dimlux Temperature Sensor - 10m Lead


Super Lumens!

Most digital ballasts, including all the variants stocked at GroWell, come with an overdrive function that enables you to safely raise the power delivered to the lamp for increased light output. Whilst this obviously demands the use of additional electricity, it then enables you to give your plants the extra push they need for bigger fruits and flowers!


If you are in the market for a new grow light remember that the digital ballast and lighting kits stocked at GroWell provide the following benefits:

- Use of Less Electricity

- Lightweight and Compact

- Cooler and Silent Running

- Consistent High Light Output

- Dimmable Output to Suit Your Grow Room

- Over-Drive the Lamp for Super Lumens!

Code Price Qty
Exolux Pro 600 Watt Dimmable Digital Ballast 1991 Exolux Pro 600 Watt Dimmable Digital Ballast
Exolux Pro 1000 Watt Dimmable Digital Ballast 1992 Exolux Pro 1000 Watt Dimmable Digital Ballast


It’s a no brainer really!

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<![CDATA[How To Survive Soaring Temperatures This Summer]]> Mon, 28 Jul 2014 15:01:29 +0000 For the avid indoor gardener, scorching hot temperatures outside plus powerful grow lights inside can only mean one thing – a very, very warm grow room!

Extreme heat Consequences of excess heat

- Plants appear stretched as the internode distance increase

- Airy open flower structures/poor fruit quality

- Increased transpiration due to high VPD

- Increased proneness to over-fertilisation due to mineral build-up in media/nutrient solution

Daytime temperature Ventilation

During the summer you will want to ensure that your ventilation system can operate to the best of its ability. Consider doing the following:


- Straighten duct runs and install metal bends rather than relying on twisted ducting

Straight Ducting

- Time carbon filter changes around summer to guarantee pressure drop is at its lowest. At the very least, replace the carbon filter sleeve to reduce dust build up resistance

Carbon Filter Sleeve- Check that your RVK fan is wired up correctly (if using this brand) – review the instructions on the plastic housing


- Employ a thermostatic fan speed controller so that the power of the fan is effectively and efficiently utilised when required

fan controllers

- Think about changing the location of your incoming air to provide a fresh and cool supply


- Ideally invest in an OptiClimate Air Conditioning System!

OptiClimate Room

Indoor Grow Lights

Obviously your lights are the main generator of heat in the grow room. To avoid creating an oven-like environment for plants, try out some of these tips:


- Time your lights to be on during the coolest part of the 24-hour cycle – i.e. at night

Nighttime temperature - Use circulation fans to mix the different areas of air between the crop and the lights

Air Circulator- Opt for air-cooled reflectors over traditional alternatives

Air Cooled Lighting- Use dimmable ballasts to reduce the light and heat output of lamps

Dimmable Ballast - Position ballasts outside of the grow room


- Reduce the number of lights in extreme cases (it’s an unpopular option but yields will often be better by providing less light at the correct temperature)


Relative Humidity

Due to the relationship between temperature and humidity, when the former rises so too should the latter in order to maintain healthy VPD and prevent excessive transpiration.

Target humidity Consequences of Low Relative Humidity (RH)

- Increased water usage and decreased nutrient uptake

- Over fertilisation

- Leaves that cup from the edges/margins inward

- Thick leathery and crispy leaves


Using a correctly sized humidifier and humidistat will address these issues relating to low RH.

HumidifiersAs a result:


- Humidifying the air will reduce the temperature – the extent of which depends on the background and target temperature and relative humidity but a 2-3oC reduction is the average amount


- Maintaining a healthy VPD will keep the stomata open and keep the plants photosynthesising

Humidifier Raising the CO2 level also helps to reduce temperature stress. Even if there are reduced stomata openings, plants will still be able to take in plenty of the highly beneficial growth gas, aiding overall development and boosting strength and tolerances to environmental issues.


Nutrient Solutions

Maintaining a cool root zone between 18oC and 20oC will provide optimum DO2 and offset high air temperatures.

Target TemperatureIn addition to this, also try to do the following:


- Check CF (EC) and pH more regularly

- If the CF (EC) level rises too rapidly, lower input/starting point

- Cover tanks to help insulate them

- Keep tanks outside of the grow room if possible

- In warmer weather, store nutrient and additive bottles somewhere cool. High temperatures can cause issues for some products featuring organic/biological components




SHOGUN SumoProtect Plants Against Heat Stress With SHOGUN Sumo Boost

Not only does SHOGUN Sumo Boost contribute towards massive yields, it also offers a good level of protection against high temperatures. The fantastic product does so by including:


Betaines - these modified amino acids perform several functions similar to those of the plant hormones cytokinins. Betaines can act as anti-stressors


Glycine betaine - has been shown to act as an osmoprotectant to enhance water utilization. There is also evidence that plants treated with betaines are more resistant to stress induced by low and high environmental temperatures


Polysaccharides and Oligosaccharides – carbohydrates and sugars that can stimulate the defence mechanisms in treated plants. A number of these have been isolated and were found to be capable of eliciting D-glycanase and a-amylase (enzyme) activity.


Lipophilic Substances – recent research has shown that application of mainly fatty acids and sterols contained within SHOGUN Sumo Boost induced significant cold resistance in treated plants



Temperatures that register above 27oC in your propagator will start to cause issues. For example, too much heat can lead to the drying out of propagation cubes – particularly Root Riot. Make sure conditions remain favourable by following these simple steps:


- Set up lighting that is adequate – not overkill

- Remember cuttings need very low levels of light to root (although greater amounts are needed to generate vegetative growth)

- Place 1 x 2ft T5 light above either size of Hi-Top Propagator for good results

T5HO Sunblaster

- If necessary, move your light higher than usual to help minimise the heat radiating into the propagator

- Provide an adequate supply of water/propagation nutrient solution as and when required

- Pay close attention to the nutrient solution temperature in aeroponic propagators. Ice packs are useful for a cooling effect.

Aeroponics Pests

Pests are more of an issue in the summer due to faster breeding times, indeed dry and hot conditions particularly favour spider mites. To prevent an attack, do the following:

- Scout for pests more often in summer – every 3-5 days is ideal

- Use a humidifier, which can slow down pest growth

- Regularly deploy predators (Nematodes for sciarid fly are very good during the summer!)

Spider MIte Preds

http://www.growell.co.uk/blog/wp-content/uploads/2014/07/howtosurvivesummer_BlogFrontpic-150x150.jpg <![CDATA[How To Survive Soaring Temperatures This Summer]]>
<![CDATA[Got Rotting Roots? Pythium: An In-depth Analysis]]> Tue, 15 Jul 2014 16:07:53 +0000 The arrival of summer inevitably sends temperatures soaring over the 25oC mark, which not only makes it difficult to control the indoor grow room environment but also causes issues with regards to the heating up of hydroponic nutrient solutions. Under these circumstances the feed mixture ends up containing less available dissolved oxygen, meaning your plants are much more prone to the notorious root disease caused by species of plant pathogenic genus pythium. Over the course of the following article we aim to reveal how pythium grows and develops in hydroponics systems, and how best to prevent and treat this invasive pathogen.

Root Rot What Is Pythium?

Pythium was misclassified for over 150 years as fungus! It is not actually one at all, and instead belongs in the family Pythiaceae of the class Oomycete. These are fungal-like organisms that grow mycelium made of cellulose and produce spores called oospores and zoospores.


Pythium is one of most the common causes of seed rot, damping-off and root rot in hydroponics. There are many species within the genus Pythium that can produce root rots, all of which have slightly different growth habits, characteristics and environmental requirements for growth.


In the same oomycetes class as pythium you’ll also find phytophthora, which leads to very similar symptoms of root rot but at the same time can also attack above-the-ground plant material causing blight, fruit rots and stem rots. Fear not though, the root rot symptoms of pythium and phytophthora are very similar and so are the preventative measures and treatments.

Pythium Where Does Pythium Come From?

Just like humans are prone to catching a cold, cough or flu bug that may be floating around, plants also find themselves susceptible to diseases in the same way. Common in nature, these plant diseases can be brought into a grow room through airborne dust, in soil or plant fragments on clothes and shoes, on infected plants from other growers, on old equipment and even in the water used to make up hydroponic nutrient solutions. Evidently then pythium is a fairly common problem, but fortunately ways and means do exist to prevent its growth and survival. Gaining an understanding of how pythium attacks plants and reproduces represents the first major step in managing this potentially destructive disease…

How pythium spreads

Pythium - Growth and Development

When a pythium infection occurs it attacks roots by producing rapidly growing mycelia that grow inside the plant (intracellular) and in the growing media immediately around the roots.


The mycelia outside the root produce tiny balloon-like organs called sporangia and in these over 100 ‘zoospores’ can be produced. Zoospores are not passively distributed like fungal spores – instead they are actually mobile in the nutrient solution using two tails called flagella to swim through it!


The zoospores travel to a portion of uninfected root, where a metamorphosis takes place known as encystment, during which time the cell walls are thickened and a germ tube is produced to penetrate the root.

Encysted zoospore

The mobile zoospore stage of the growth and development of Pythium have given them the common name ‘water moulds’. Although these zoospores are efficient swimmers, and are the principle way in which pythium spreads though a hydroponic system so quickly, they are not very persistent outside of their water based habitat.


However, pythium can also produce ‘oospores’ from its mycelium, which are more persistent and are able to survive outside of ideal conditions for their germination. Oospores spread via wind or water, and like fungal spores prove to be very persistent and difficult to eradicate.


When either an oospore or zoospore initiates an infection, the spore germ tube directly enters the plant tissue. The mycelium of the growing pythium outside of the root tissue can also enter the roots to spread its infection before spore development. Once the mycelia are inside the root tissue, the pythium produces enzymes that break down the pectins holding the cells together. This is why infected roots lose their integrity and go mushy.


Generally, if pythium infects a newly germinated seedling or rooted cutting, then the plant will often die at a young age. If infection occurs on a well-developed plant the advance of the infection can be stopped at that point thanks to its own immune responses keeping the infection localised. This results in the decay of some – but not all – root material. However, as zoospores are produced and released into the nutrient solution at a rapid rate, more roots are infected. If the cycle of zoospore production and infection is not stopped, then the disease can decimate the whole root system very quickly.

Struggling seedling Pythium – Symptoms

The first sign of pythium taking hold of the roots is a discolouration from white to beige/yellow/brown colour, followed by the gradual shift to a soft and mushy texture. In an early infection, you can often tug at a root you suspect of having the infection, and the outer root sheath will come off leaving the central core. Plants spotted with these early infections are capable of recovery if the right approach is adopted.


If you haven’t had the opportunity to check your root system, or you are growing in a system that uses growing media and root inspections prove difficult to carry out, then you may find the first indication of a pythium outbreak will be a rotten egg-like, sulphurous smell coming from the nutrient solution. This is often associated with a drop in solution pH, at which point plants can still recover if you take immediate action.


In a situation where there are no initial clear symptoms of pythium, you may find that the stunting of plant growth and unexplained wilting are the first indicators of a problem, typically followed by the yellowing of the leaves and leaf drop. Already well into the disease, the plant is unlikely to survive.


For young plants such as cuttings and seedlings, pythium often causes the stem to rot at the base, so there’s nothing to stop them from falling over and dying. Indeed, the stems of most plants that have constant contact with damp growing media can be at risk of stem rot. Where possible then, you want to ensure the stem does not remain in damp growing media over any prolonged period of time.

Seedling with pythium Pythium - Causes

Although pythium is fairly common, many growers manage to avoid it all together. How? Well, pythium acts in an opportunistic manner, and given the right conditions it will simply flourish. But when presented with less than ideal conditions and healthy robust plants, pythium will find it very difficult to make successful infections.


As mentioned at the start of the article, high root zone or nutrient solution temperatures will support the growth and development of pythium. The high temperature causes low levels of dissolved oxygen in the nutrient solution, leading to poor root growth and function, increasing the risk of infection. Over-watering plants in soil or coco also produces a saturated root zone that is lacking in oxygen, and these anaerobic conditions make it very difficult for roots to thrive and very easy for pythium to spread. Make sure your growing medium has good drainage and is only watered as and when it’s needed.


Root damage is a major cause of infection. Pythium is opportunistic and will favour entry through a damaged area, which often affects young plants during transplanting. Insects feeding on the root system, such as fungus gnats, are also capable of creating many wounds in which pythium spores can easily infect the plant.

Root damage

Excess nitrogen is a contributor to the onset of infection by pythium. Nitrogen is needed by plants in relatively large amounts, but too much can generate soft weak growth that happens to be more prone to diseases. Avoid over-supply of high nitrogen ‘grow’ base nutrients or try and use additives such as SHOGUN CalMag in high doses.


Poor grow room hygiene and failure to remove dead plant material from around plants are sure fire ways to invite trouble into your grow room. You should immediately clean up any dead leaves and pick out any floating root fragments that are still in the nutrient solution. Re-using growing media is fine when you have had successful previous crops but if you fear the possibility of an infection don’t risk it, replenish with new stock.


Pythium – Prevention

One of the best methods for preventing pythium from occurring in recirculating hydroponic systems is to maintain the optimum nutrient solution temperatures by insulating the reservoir and using a chiller. Most pythium species responsible for hydroponic crop damage are very active at a temperature range of 20-30C, so try and keep the solution at a cool 18-20oC.

Target Temperature Frequent reservoir changes for a recirculating hydroponic system is a simple yet effective way of ensuring the build-up of zoospores does not happen. Ideally, you should aim to carry out weekly changes of your nutrient solution.


It sounds obvious, but you cannot underestimate the importance of keeping clean and tidy! For starters, all dead and/or decaying plant material must be moved far away from the growing area. Sterilising, or at the very least, cleaning hydroponic equipment between crops is a must - we recommend using RoomClean for the task.

Code Price Qty
RoomClean Concentrate - 1 Litre 1498 RoomClean Concentrate - 1 Litre
RoomClean ready to use Sprayer - 750mls 1499 RoomClean ready to use Sprayer - 750mls


Maintain a good growing environment! Stressed plants are more prone to disease than healthy plants so you’ll want to closely control the temperature and humidity to make the area as near to perfect as possible. Remember the growing environment is arguably the most important overall factor when you’re growing plants indoors!


A great step towards complete prevention of pythium is to use beneficial biological products because these are not only easy to apply, but also extremely effective.


Pythium – Prevention Products; Beneficials

Beneficial biological products are a completely natural and very low-maintenance means of preventing disease. Using beneficial microbes in the growing media or nutrient solution not only makes the root system more robust, it also crowds out and antagonises pythium.


Mykos is a great product containing an aggressive species of Endo Mycorhizae that forms a powerful symbiotic relationship with the plants roots. Designed for application at the transplanting stage, Mykos will ensure the plant has increased access to water and nutrients as well as improving disease resistance in the root zone.

Code Price Qty
Xtreme Gardening Mykos Root Paks - 50 packs 5400 Xtreme Gardening Mykos Root Paks - 50 packs
Xtreme Gardening Mykos 1lb 5401 Xtreme Gardening Mykos 1lb
Xtreme Gardening Mykos 2lb 5402 Xtreme Gardening Mykos 2lb


Canna AkTRIvator features the beneficial fungus Trichoderma, which produce enzymes that antagonise pythium infections by degrading their mycelia. These are very effective preventative microbes and also stimulate root growth.


Note: it is currently not advised to add products containing Trichoderma at the same time as those with mycorrhizae due to competition between these two fungal species. You could inoculate with mycorrhizae and allow for good establishment to occur over 4-6 weeks, then inoculate with Trichoderma and not see too much inhibition or competition, but studies have shown that applying mycorrhizae and trichoderma simultaneously can lead to an inhibition of mycorrhizae establishment.


Root Rot Stop is fantastic for pythium prevention that uses bacillus strains of bacteria. The particular strains involved and ways of working have been kept a secret, but it will successfully prevent the onset of the disease as well as clearing up pythium that has already caused an infection.

Code Price Qty
Root Rot Stop - 250mls 3610 Root Rot Stop - 250mls
Root Rot Stop - 1 Litre 2305 Root Rot Stop - 1 Litre


Other products that are excellent at building good populations of beneficial biology to improve root growth, health and prevent disease include Ecothrive Charge and Vita Link Bio-Pac.


Enzyme-based additives including Cannazym, Hygrozyme and House & Garden Multi Zyme are also useful for preventing pythium, by degrading dead root material to keep the root zone clean of dead and decaying tissues.


Pythium – Treatment Products; Sterilises

In instances where a bad problem is found it is often good practice to sterilise the solution to kill all living microorganisms in the nutrient solution. This can be done effectively with Pythoff, which uses chlorine compounds at 1% to eradicate pathogens, but you will need to apply regularly as the chlorine compounds do dissipate over time. Using plenty of Pythoff for a few weeks, then following it up with Root Rot Stop is a good approach to getting on top of a problem.

Code Price Qty
Pythoff - 1 Litre 3200 Pythoff - 1 Litre


Note: Pythoff will destroy all living microorganisms so obviously don’t add any beneficial biological products at the same time.


Oxy-Plus (Hydrogen Peroxide) is a brilliant product for disease prevention, but at the concentrations necessary to kill active pythium growth and spores it will also damage plants. Great at a high dose for cleaning, Oxy-Plus is less effective when regularly added to the nutrient solution.


Ozone and UV treatment of the nutrient solution both kill pythium spores in the nutrient solution, but these prove to be no more than moderately effective overall. This is because they only work at the point of contact, so zoospores released within the root zone still have the opportunity to travel to other roots and cause infection (only the spores that travel past the UV steriliser or Ozone outlet are killed). Also these methods of sterilisation degrade the chelated nutrients in the solution, meaning you must use an additive to replace the degraded chelates. The better approach is to use a product that travels throughout the whole system to work against the pythium, such as Pythoff or Root Rot Stop.


A Step-by-Step Guide to Dealing with A Previous Pythium Infection

If you have recently had an issue with pythium and are trying to get back on track, here is a list of recommended steps to prevent it from returning:

Sponge and water


1.) Clean the hydroponics system using soapy water and a soft sponge, NOT an abrasive (when plastics are scratched with a scouring pad it leaves an ideal site for spores to hide).


2.) Replace any pipework that cannot be sufficiently cleaned.


3.) Follow-up with a high dose of a steriliser, e.g. Oxy-Plus.


4.) Sterilise for 24 hours.


5.) Inoculate plants at an early stage with beneficial microbes to help with disease defence.


6.) Replant carefully and only when plants are very healthy and itching to go.


7.) If the above does not work and pythium comes back then consider all possible sources of infection and review your growing practices to stop it from taking any further hold. Changing the growing system(s) at this point is recommended.

Pythium in NFT Note: if you have to replace the growing system and pythium still returns then there must be another source of the disease, and the type of hydroponics system being used probably isn’t the most suitable for you – in which case, try a different one.


Please submit any questions you have about preventing or dealing with pythium to our team of growing experts, who are always available to help in store and online.

http://www.growell.co.uk/blog/wp-content/uploads/2014/07/Root-Rot-cover-150x150.jpg <![CDATA[Got Rotting Roots? Pythium: An In-depth Analysis]]>
<![CDATA[Everything you need to know about nutrient chillers!]]> Wed, 02 Jul 2014 16:11:43 +0000 Why use a Nutrient Chiller?

During the hotter months of the year, a Nutrient Chiller enables you to maintain optimum nutrient solution temperatures of 18-20oC for maximum plant growth.

Target Temperature The problem with ignoring the heat is that the consequential warm water contains less dissolved oxygen than a cooler form, leading to poor root growth and functionality as well as increased risk of root diseases - e.g. pythium.

root-rot Frequently irrigated hydroponics systems like Bubblers/DWC, NFT and Flood and Drain will greatly benefit from close control of nutrient solution temperatures, since the roots are most susceptible in these particular types of set ups.

DWC, NFT and Flood and Drain 

To accureately monitor the temperatures of feeds we highly recommend getting yourself an Accuread Digital Nutrient Thermometer, which is available at a very affordable price!

Code Price Qty
Accuread Digital Nutrient Thermometer 1213 Accuread Digital Nutrient Thermometer


Basic Nutrient Chiller Usage Guidelines

Wherever and whenever possible, you should position your Nutrient Chiller outside of the grow room/grow tent. Remember, each unit is basically a mini-refrigerator so expect a little heat to be generated (externally, obviously!) from the parts that are working hard to provide the cooling effect.


Correctly spec the Nutrient Chiller for the volume of water being treated. Indeed rather than selecting a model that will only just accommodate your cooling needs, go for one clearly capable of dealing with the amount of water you intend to use. After all - the bigger the chiller, the less time is required to reach the target temperature.

Nutrient Chiller Also, correctly spec the water pump to feed the Nutrient Chiller - the rate of water flow through the unit is important.

Water pumps Use 13mm pipe work (Flexi-Pipe or Iceline Pipe) and a 13mm inline filter on the water feed line to remove any particles or debris.

Iceline Pipe Work Make sure you try and clean the Nutrient Chiller after every crop!


Chiller Models

Usage guide

(For the AQ7000, use an inline valve to reduce flow – particularly if you’ve got a short pipe run).

Code Price Qty
Hailea HC-100A Nutrient Chiller 1792 Hailea HC-100A Nutrient Chiller
Hailea HC-300A Nutrient Chiller 1796 Hailea HC-300A Nutrient Chiller
Hailea HC-500A Nutrient Chiller 5361 Hailea HC-500A Nutrient Chiller
Hailea HC-2200A Nutrient Chiller 5274 Hailea HC-2200A Nutrient Chiller


Setting Up A Nutrient Chiller With A Flat Tank (NFT)

This example involves the use of a Hailea HC-100A Nutrient Chiller for cooling the nutrient solution in a NFT Gro-Tank 424.

Room layout

1.) Place the Nutrient Chiller in a well-ventilated area – ideally outside of the actual grow room. The unit needs to sit above the height of the tank, so raise it with a small stand or platform if necessary.


2.) Locate an MJ1000 Maxi-Jet Pump or Idra 400 Pump at the end of the tank that is nearest to where you have positioned the Nutrient Chiller. Push down on the top of the pump to attach it to the base of the tank.

Code Price Qty
MJ1000 Pump - 1,000 Litres per Hour (for Gro-Tank 1000) 0049 MJ1000 Pump - 1,000 Litres per Hour (for Gro-Tank 1000)


3.) Take a piece of 13mm Flexi-Pipe or Iceline Pipe (latter recommended for extra help keeping temperatures down) and run it from the outlet of the MJ1000 Maxi-Jet Pump to the inlet of the Nutrient Chiller.


4.) Take another piece of 13mm Flexi-Pipe or Iceline Pipe and run it from the outlet of the Nutrient Chiller to the furthest away end of your tank. For the chiller to work properly, the open part of the pipe must remain submerged in the nutrient solution.

Code Price Qty
Iceline 13mm - per metre 4473 Iceline 13mm - per metre


5.) Sit a MiMouse 30 Pump at the opposite end of the tank to the MJ1000 Maxi-Jet Pump and run this to stir the nutrient solution.

Code Price Qty
MiMouse 30 - 300 Litres per hour 13mm outlet 1195 MiMouse 30 - 300 Litres per hour 13mm outlet


6.) Set up a Professional Air Circulator near to the Nutrient Chiller to keep the unit cool.

Code Price Qty
Small Professional Air Circulator - 20cm (8 inch) 0353 Small Professional Air Circulator - 20cm (8 inch)


Using a Nutrient Chiller With A DWC System

If you’re using one or more DWC system where there is water in it/them for long periods of time, especially when plants are small, the bucket(s) will be subjected to a lot of radiated heat. Oxy-Dripper System

The temperature needs to be set a few degrees lower than the required system temperature. Always go for a size of Nutrient Chiller that is easily capable of managing the volume of water you are trying to cool. For example, if you have a 6-pot DWC system, spec a HC300 to quickly and efficiently chill the returning warm water during a drain cycle.

IWS Bubbler System Alternatively set the HC100 temperature much lower than required to compensate for the rapid increase in temperatures. Note: using this method is very difficult to get right, takes longer to chill the water and becomes more and more difficult as the holding volume of water in the reservoir diminishes.


Cleaning A Nutrient Chiller

It is very important to remove mineral deposits and lime scale from your Nutrient Chiller. We have found the following method to be the best:


1.) Fill the Nutrient Chiller with clear pickling vinegar

2.) Leave for 24 hours

3.) Flush with water

http://www.growell.co.uk/blog/wp-content/uploads/2014/07/nutrient-chiller-web-150x150.jpg <![CDATA[Everything you need to know about nutrient chillers!]]>
<![CDATA[Here's a game changer! The OptiClimate System]]> Mon, 19 May 2014 11:10:43 +0000 What is an OptiClimate System?OptiClimate System

Groundbreaking. Growth-boosting. Game-changing.


The OptiClimate System is a water-cooled climate control unit purposely designed for the indoor horticultural market.


Large-scale grow tent owners actively extracting air and introducing fresh supplies can use this awesome product to establish precise temperatures and then rely upon it to respond when necessary to hold them steady.


The other exciting option is for people that have opted not to use a tent. An OptiClimate System provides the basis for building the ultimate ‘closed loop’ plant-growing chamber – an incredible secluded paradise, far removed from neighbouring indoor and outdoor environments.


Pleasingly this dream set up is achievable in the simplest form by having a normal light arrangement, growing system, humidifier and a CO2 generator and CO2 controller (you want minimum contact with the outside world, meaning no intake of air, which of course would contain carbon dioxide – so it must be added).

Basic OptiClimate Set UpFurthermore, when the OptiClimate System is used alongside premium ‘companion’ products (i.e. they’re made to work with each other) like the Dimlux Ballasts and the Maxi Controller (syncs the OptiClimate, Dimlux and CO2 equipment), something special happens – the different technologies actually communicate back and forth and react in the best interest of your plants! For example, if your grow room unexpectedly becomes much hotter, the controller will dim the lights and increase the air-cooling activity of the OptiClimate System.

OptiClimate and Dimlux

Will an OptiClimate System suit my growing space?

You’ll find 4 different versions of the OptiClimate System to choose from, starting with a model for areas containing 6 x 600w/9 x 400w lights and progressing up to one that accommodates 24 x 600w/35 x 400w lights. These do a sensational job in full grow room set ups, but at present only the OptiClimate 3500 System is suited to a grow tent (the Titan+ BudBox, Titan2 BudBox and Titan3 BudBox).


What are the advantages of an OptiClimate System

There are numerous terrific benefits associated with the OptiClimate System. Here's a brief overview of some of the major plus points:

OptiClimate System- You can establish and maintain a perfect growing environment for 365 days of the year

- You are able to achieve reliably outstanding results by overcoming seasonal constraints

- You no longer need to add radiators and thermostats in the winter and up the number of fans/upgrade to bigger fans/set up mobile air conditioners in the summer

- You find large-scale air exchange becomes a thing of the past (only a small extractor fan and carbon filter are required to achieve negative pressure)

- You can effectively and efficiently introduce CO2 into your grow room, leading to increased vegetative growth, improved yields and a reduced flowering cycle

- You are able to stop pests and disease from entering your room by doing away with air intake activities.


This is only the tip of the iceberg in terms of what the OptiClimate System can do for you. Let us now look at the advantages a little more closely...


You can create the perfect climate and maintain it

An OptiClimate System allows you to overcome the impact of seasonal weather variances, since it includes both cooling and heating elements. All of a sudden super hot summer days and freezing cold winter nights pose absolutely no threat to your plants because they get to enjoy constant temperatures throughout the whole year!

Summer and winterAir is evenly distributed across the growing area, meaning each and every plant experiences exactly the same conditions regardless of where they are located!

Even air distributionA consistent, well-spread, near-to-perfect climate will go a long way towards guaranteeing that the plants produce equally fantastic performances, enabling you to achieve reliable and outstanding yields on a continual basis.


You can cool, heat, circulate, dehumidify and filter air with a single appliance

Thanks to the multifunctional nature of the product, the OptiClimate System can be trusted to maintain your chosen grow room temperature and humidity settings. It will closely monitor the environment and promptly respond if an issue arises by picking and applying the most appropriate air treatment(s). This certainly beats fiddling with separate pieces of equipment, saving you a whole lot of time and effort!


You can leave the unit to automatically adjust grow room conditions

Once you’ve entered minimum and maximum temperature targets for night and day, and a maximum humidity target for the night, the OptiClimate System will take care of the rest! It operates entirely automatically!


A light sensor detects when your lights go out – triggering the heating mode (and also the dehumidifying element if necessary), and similarly notices when they come back on again – this time activating the cooling mode (and also the dehumidifying element if necessary).

Lights on mode

Lights off mode

Unexpected heat waves and cold snaps are not a problem as the unit makes instant adjustments to restore the balance. That means you don’t need to be present to oversee it all!


You can use it indoors and in greenhouses, for normal and multi-layer set ups

The OptiClimate System aims to improve the lives of serious UK growers after earning itself a superb reputation in the commercial greenhouses of Holland. You’re looking at a high performance product of genuine quality that is trusted by professional growers with extensive single and multi-layer set ups. However, the unit also proves to be full of promise for people running much smaller indoor operations.

Greenhouse set up You can preheat your grow room during night-to-day transitions to stop bud rot

Evidence of the care and consideration that has gone into the design of the OptiClimate System is clearly apparent when you check out the pre-heat function. Upon activation this intelligent feature helps to stop condensation from affecting plants, making it more difficult for botrytis and grey mould to take hold.

Preheat function

Fruits tend to cool down a great deal over night, but then as the air temperature in the early morning typically rises far quicker than the temperature of the fruit, condensation forms on their cold soft surfaces – inevitably inviting conditions for botrytis. The pre-heat function combats this issue by instructing the OptiClimate System to begin warming the growing area an hour before the lights activate, so that when they do turn on, the temperature quickly matches your daytime target.


You can ensure the temperature doesn’t free-fall during the turning off of lights

Another display of forward thinking by the smart folks responsible for the OptiClimate System is the slow cool down function. It ensures that the temperature does not drop too rapidly once the lights have been switched off, which would otherwise shock your plants and potentially stunt their growth. Over the first hour of the dark period the unit will slowly cool the room, allowing for a gradual decrease in temperature towards the desired nighttime setting.

Slow cool down function

You can program the unit with ease using the clear and simple remote control

A product is of little merit if it has all the greatest features in the world but no means of managing them for fast and effective use. Fortunately the OptiClimate System includes a handy controller that avoids complications! The large and highly visible main screen shows a snapshot summary of all the key factors (mode – day or night, fan speed, temperature, time, etc.), whilst a simple series of buttons facilitates quick selections and easy alterations without forcing you to trawl through countless menus. Comprehensive instructions are also provided to ensure you feel 100% confident operating the unit.

OptiClimate Controller

You can avoid drawing in and extracting out large volumes of air

To keep the inside of a ‘closed loop’ grow room at its best and practically eliminate the impact of any external forces, air intake is simply not possible. Although you must subsequently add and manage the missing CO2 for photosynthesis with a generator and controller, this does significantly reduce the chances of disease outbreaks and pest infestations.


The carbon filter on the OptiClimate System helps you to lower the concentration of odours in your grow room, reduce noise and prevent the entry of mould. It also removes the need for a large separate extractor fan and carbon filter – allowing you to save money by scaling-down extraction activities and getting smaller fan and filter models instead.

Carbon Filter You can safely introduce CO2 to enhance the growth rates of plants

Installing an OptiClimate System into a grow room that has been cut off from nearby surroundings and features no active air intake will require you to efficiently introduce and run CO2 dosages. This actually represents a huge advantage! Since there is also very little air extracted from the area, carbon dioxide can be added without waste – i.e. all of the growth gas generated stays within your grow room until the plants have used it.

CO2 Generator Carbon Dioxide possesses the ability to completely transform a crop – most plants grow faster (up to 40%) and larger and yield more as a result of enhanced CO2 levels due to improved rates of photosynthesis and a reduction in water loss. There are also many other benefits for plants including greater resistance to temperature extremes and other forms of stress, better growth at low light intensities, improved root/top ratios and less likeliness of damage being caused by air pollutants.


You can use one unit to cool two grow rooms

So far the OptiClimate System has been discussed from the viewpoint that you intend to take complete control of conditions in a single grow room or manage temperature and humidity in a tent, yet another option does exist – to cool two rooms at the same time. Using the optional 3-way valve and an extra temperature sensor, you can instruct it to simultaneously reduce temperatures in a separate day room and night room (only cooling is possible in this mode). Now there’s no need to invest in the two large extractor fans and fan controllers normally required for such a scenario.

Cooling two rooms You can confidently steer clear of safety concerns

The OptiClimate System covers all of the bases when it comes to protecting your plants, equipment and buildings from fires and leaks.


Every effort has been made to put your mind at ease regarding fire safety. Firstly the electrical components and connections are fitted inside robust, flame resistant steel casing. Secondly, it uses ceramic heating – the most reliable and trustworthy type of electric heating around. And thirdly, an in-built temperature safety switch can turn off lamps if the temperature reading soars above your indicated maximum limit (which might occur due to an obstructed water supply for example).


Similarly, to counter the threat of flooding the unit includes an in-built water leakage safety switch. Any water that leaves the piping network, collects on the floor and hits the sensor will alert it to shut off the supply – most likely because of a burst pipe, broken connection or blocked sewer.


Finally, there is the option to use an excellent alarm system that notifies you of any issues and saves these message for referencing at a later date. You’ll receive an SMS alert to your phone upon detection of a fault (excessive heat or a leak) and this will then be recorded by the Alarm Log function.

Heat warning You can run the unit all day and night and not cause disturbances

The OptiClimate System is extraordinarily quiet! With acoustic insulation effectively soundproofing the unit and vibration springs helping to keep it stood still and silent, you could quite literally hear a pin drop!


Now you know some of the major selling points that underpin the brilliance of the OptiClimate System, read on to discover a bit more about setting one up and getting it to work.


How does the OptiClimate System work? And what is the best way of setting it up?

Depending on the conditions inside your grow room and the target temperature, the OptiClimate System will either cool down the air with water or warm it up by using ceramic heaters. There is an inlet that you connect to your cold water supply for cooling the air and an outlet for transporting the resulting warm water to a drain or storage tank (some people even use this ‘waste’ product for central heating!).

OptiClimate Overview

OptiClimate Overview

As has been previously mentioned, the unit also dehumidifies the air during the cooling process. Moisture extracted from the air enters the condensation drain, which you connect to a pipe that either feeds into your main drain, nutrient tank or humidifier reservoir. The RO water (completely purified, containing no trace elements) is suitable for use straight out of the OptiClimate System, but you may need a condensation pump to direct it to the chosen destination.


Important note: if you intend to operate a humidifier in a room with the OptiClimate System, you must use RO water (either from the condensation drain or from a separate supply treated by a Reverse Osmosis System). Failure to do so can lead to unwanted mineral deposits being left on your reflectors and in parts of the unit itself. This is a serious issue that actually voids the warranty.

Reverse Osmosis System The OptiClimate System should be fitted with vibration springs and positioned on a stand/raised surface (recommended) or alternatively suspended from the ceiling.

Vibration Isolator Spring

If you’re not going to opt for vibration springs, it needs mounting so that the side of the condensation drain sits at least 1cm lower than the other side – thus ensuring the condensation water flows properly.


For the most efficient use of air and easy inspection of internal components, a distance of 15cm-30cm is required between the grow room wall and back of the unit. Likewise, establishing a gap of at least 10cm between the grow room ceiling and top of unit will help you to avoid any contact noises.

Gap from wall/ceiling Rather cleverly the OptiClimate System can be adjusted to account for the shape of your grow room. The standard set up suits a wide area but the air outlet is actually re-positionable, allowing you to move it to the short side of the unit if you have a narrow space.

Repositionable air outletRepositionable air outlet In terms of the ducting, keep everything as big as possible (i.e. don’t reduce the 250mm/10 inch spigot size) and as short as possible. Remember long lengths of ducting and bends will reduce the efficiency of your airflow. Run the ducting down through the middle of your lights and pierce small holes into it for the air to escape, thereby ensuring all areas of your room benefit from the cooling effects.


You then just need to make a small number of electrical connections within the OptiClimate System (these are thoroughly explained in the instructions), before plumbing and wiring in the unit to your water and electrical supply respectively.


Taking the remote control, enter in details of the desired minimum temperature (night) and maximum temperature (day), update the standard settings (e.g. time), configure the timer and activate the special functions you want to run. Afterwards you’ll want to check the status screen and Alarm Log every now and again to monitor how things are progressing.


What do I get with the OptiClimate System? And what else will I need?

There are currently 4 different versions of the OptiClimate System available:

-       OptiClimate 3500 (3500 watt capacity suits 6 x 600w lights or 9 x 400w lights)

-       OptiClimate 6000 (6000 watt capacity suits 10 x 600w lights or 15 x 400w lights)

-       OptiClimate 10000 (10000 watt capacity suits 16 x 600w lights or 24 x 400w lights)

-       OptiClimate 15000 (15000 watt capacity suits 24 x 600w lights or 35 x 400w lights)


In terms of grow tents, if you have a Titan+ BudBox, Titan2 BudBox or Titan3 BudBox you can use the OptiClimate 3500 to cool, heat, dehumidify, circulate and filter the air.


Each model is supplied with a magnetic valve, a water leakage sensor, an automatic moisture meter, a remote control, a room temperature sensor and a carbon filter.

Code Price Qty
OptiClimate 3500 Pro 3 System 5310 OptiClimate 3500 Pro 3 System
OptiClimate 6000 Pro 3 System 5311 OptiClimate 6000 Pro 3 System
OptiClimate 10000 Pro 3 System 5312 OptiClimate 10000 Pro 3 System
OptiClimate 15000 Pro 3 System 5313 OptiClimate 15000 Pro 3 System

You will need the following items to get it operational:


- 16mm Pipework: required for transporting the cold water from your source to the inlet, and for transporting the hot water from the outlet to the drain or storage tank (15mm pipework connections are standard on the OptiClimate System but we recommend using a reducer on 16mm pipework because this proves easier to find and buy)


- 13mm Pipework: required for taking away the water collected from the condensation drain


We also recommend investing in a small selection of helpful accessories:


- Anti-Vibration Springs: 4 are required, 1 for underneath each corner of your OptiClimate System. These stop the unit from shaking and creating noise, and also ensure the condensation drain works as intended.

Vibration Isolator Spring

Code Price Qty
Anti-Vibration Springs for OptiClimate 3500 Pro 3 Systems (pack of 4) 5413 Anti-Vibration Springs for OptiClimate 3500 Pro 3 Systems (pack of 4)
Anti-Vibration Springs for OptiClimate 6000 Pro 3 Systems (pack of 4) 5315 Anti-Vibration Springs for OptiClimate 6000 Pro 3 Systems (pack of 4)
Anti-Vibration Springs for OptiClimate 10000 Pro 3 Systems (pack of 4) 5324 Anti-Vibration Springs for OptiClimate 10000 Pro 3 Systems (pack of 4)
Anti-Vibration Springs for OptiClimate 15000 Pro 3 Systems (pack of 4) 5414 Anti-Vibration Springs for OptiClimate 15000 Pro 3 Systems (pack of 4)


- Plenumbox: this connects to the air outlet of your OptiClimate System, enabling you to more easily attach ducting to it.

Plenumbox To go on and properly establish a ‘closed loop’ room, you should set up these items:


- CO2 Generator: required for boosting the overall amount of carbon dioxide in the grow room. With no active air intake, a rich source of carbon dioxide is needed to allow plants to carry out the all-important process of photosynthesis. We recommend opting for a Growth Gas Generator

Growth Gas Generator - CO2 Controller: required for monitoring the carbon dioxide being introduced into the grow room. It will switch on/off the supply depending on the present conditions. We recommend choosing the superb Maxi Controller

Maxi Controller - Professional Humidifier: plants demand different levels of humidity as they progress through the growth cycle – one of these units enables you to precisely tailor the amount of water vapour in the air at any given time

Professinal Humidifiers For rooms containing an OptiClimate System and humidifier, you absolutely have to feed the latter with RO Water or else the warranty is voided. Either install a Reverse Osmosis System or use a Condensation Pump to recover the RO water dehumidified by the OptiClimate System and then direct it to the reservoir serving the humidifier.


The next step in transforming a grow room into the ultimate ‘closed loop’ set up involves upgrading your ballasts to Dimlux! More information about these incredibly innovative products and a thorough explanation of how they work with the OptiClimate System and Maxi Controller will be covered in a soon-to-be-released article. Stay tuned!  


Where can I see an OptiClimate System in action?

After reading through all the positive remarks in this write up, you might just have had your appetite whetted for the OptiClimate System. It’s understandable – you’re looking at an uber impressive bit of kit!

OptiClimate Room To get a true sense of the capabilities of this pioneering product, you need to observe one of our fantastic in-store working displays. Nothing beats a live demonstration, or the opportunity to talk to an expert who knows the OptiClimate System inside and out!

OptiClimate Room We’ve got units set up in grow tents at GroWell Wembley and GroWell Sheffield, but the real showstopper can be found anchoring a specially created ‘closed loop’ room in GroWell Coleshill. Feel the cooling effect of the OptiClimate System as it maintains optimal plant-nurturing temperatures despite the presence of 6 powerful 600w grow lights. Wonderful stuff!

http://www.growell.co.uk/blog/wp-content/uploads/2014/05/opticlimate-web-150x150.jpg <![CDATA[Here's a game changer! The OptiClimate System]]>
<![CDATA[The Definitive Guide To Dealing With Spider Mites]]> Tue, 29 Apr 2014 14:45:05 +0000 How to Spot Spider Mites

Spider mites are tiny little insects that prove to be very difficult to spot to the untrained naked eye. The average body length is approximately 0.75-1mm and yellow/cream or red in colour. When you look up close, you can see two dark spots on the back of some species – these carry the name “Two Spotted Spider Mites”.

Spider mites up close

Spider mites feed off the sap of plants, causing the leaves to discolour. Usually, this damage appears as small white dots on the upper surface of the leaf.

Spider Mite Damage

If the initial destruction is allowed to continue, a whole leaf turns a speckled white/yellow, sometimes also with golden brown patches.

Further mite damage

Spider mite marks

Furthermore as the mites remove the chlorophyll and a severe attack hits full flow, the leaves will begin to die off.


Spider mites also produce webs – these can be seen in between leaves at first or completely covering the plant during a particularly bad bug residency. The webs are used as transport paths, which enable the mites to completely swarm the plant. Mature webbing also works like a barrier and protects the mite colonies underneath, subsequently restricting air flow and water loss from plant tissue that sometimes leads to problems with fungal pathogens – e.g. botrytis (bud rot).

Spider mite webbing

Spider mite web

Spider Mites Life Cycle

Temperature is very important when it comes to the spider mite reproduction cycle. At 12°C no development occurs, whereas at 25°C a freshly laid egg will hatch, grow into an adult mite and lay more eggs after only 10 days. Worryingly, at 30°C this time comes down to just 7 days! Females can produce up to 150 eggs in their life, laying around 10 eggs per day. These are 0.14mm in diameter and transparent at first, eventually turning white to light yellow. Spider mites reproduce rapidly, especially when conditions register above 28-30°C and below 40% relative humidity. In this sort of setting there is an increasing level of spider mite activity and resulting bug-related damage.


Sneaky Spider Mites

When the growing environment changes adversely, female spider mites enter a period of hibernation known as ‘Diapause’. Trigger effects include:


- Falling temperatures

- A decline or deterioration in food supply


A lot of people terminate their crop after a severe attack, hoping that the spider mites will leave the grow room to hunt for other sources of food. Unfortunately though, this is not usually the case. Instead the spider mites go into a dormant condition, hidden within the grow room, enabling them to last for up to a year despite eating nothing and laying no eggs. As soon as conditions become favourable again, the females awaken and restart egg production.

Spider Mite Fumer If you have had a bad infestation, the best approach is to keep the temperature high after harvest and use the smoke bombs we sell called Midi Fortefog P Fumer. These will kill active spider mites with a high concentration of smoke – use one per 20m3 at the end of a crop.

Code Price Qty
Midi Fortefog 'P' Fumer - 11g 0479 Midi Fortefog 'P' Fumer - 11g


Dealing with Spider Mites

At GroWell, we believe in Integrated Pest Management (IPM). This involves:


- Prevention: through good hygiene and general monitoring

- Biological control (natural predators): to control pest populations (most effective as a preventative or at first sign of attack)

- Selective use of pest sprays: to reduce numbers quickly and efficiently in moderate to extreme cases


IPM stresses how important it is to be proactive when dealing with pests. The steps below will help you to adopt this approach, advising on what you can do to block out spider mites and instructing on how to react upon attack.


GroWell Top Tips On Preventing Pests

1.) Clean your room before every new crop cycle. A decent product to use is RoomClean, a plant friendly room cleaner and disinfectant.

Clean grow room

Code Price Qty
RoomClean Concentrate - 1 Litre 1498 RoomClean Concentrate - 1 Litre
RoomClean ready to use Sprayer - 750mls 1499 RoomClean ready to use Sprayer - 750mls


2.) Try to be self-sufficient and take your own cuttings. If you do use cuttings other people have given you, make sure that you treat each cutting before putting them in your grow room.

Taking cuttings

3.) For early identification of pests and to reduce the chance of them reaching your plants, we recommend that you use Horti-Shield Yellow Sticky Traps. Place the traps near all entry points, such as air inlets, and also in the middle of your room hanging above the plants.

Hanging traps It’s also a sound idea to remove the protective layer from one side only and place the sticky traps at the base of your plants to monitor and trap fungus gnats.

Sticky trap

Code Price Qty
Horti-Shield Yellow Sticky Insect Traps 1926 Horti-Shield Yellow Sticky Insect Traps


4.) The most common way for pests to get into your room is by ‘hitching a ride’ with you, either on your clothes or in your hair. If you go outside to places where there are loads of plants, such as local parks, wildlife areas or other greenhouses and grow rooms, we advise that you take a shower and change your clothes before entering your own grow room. Using a paper suit will help, just step in it and zip up to prevent any pests from jumping off of you.


5.) Pests can also enter your room through your intake fan. We highly recommend installing a Horti-Shield Bug Blocker to prevent this from happening – simply attach one to your intake fan to establish a barricade that is effective against all sorts of pests including spider mites.

Horti-Shield Blocker 6.) Neem Repel and SB Plant Invigorator are two naturally derived pest sprays that can deter and kill most plant pests. Please note: while both Neem Repel and SB Plant Invigorator are predominately considered to be preventive measures, they also work well at the first sign of attack. Since the two products do kill all insects, we don’t advise that you apply them during use of natural predators. However, you may have no choice but to spray your plants with one or both of these products if they become infected with pests. SB Plant Invigorator will destroy whatever insects it hits, but there are no long-term persistence issues – so you could quickly build up predators again after application.

Neem oil

Code Price Qty
Neem Repel Concentrate - 250mls 1110 Neem Repel Concentrate - 250mls

Out of stock

SB Plant Invigorator - 250mls 1226 SB Plant Invigorator - 250mls


7.) Make sure you inspect your plants for pests on a regular basis, checking the tops, but mainly the undersides of leaves. We recommend an on-going ‘5 Day Bug Check’, generally looking for spider mite and associated mite damage. A magnifier will help with the task, like our convenient, pocket-sized Active Eye model.

Code Price Qty
Active Eye Magnifier 0908 Active Eye Magnifier


8.) If you find an outbreak of pests, use a spray to reduce the number quickly and efficiently.

Pyrethrum spray

Pesticide Sprays

If you don't notice spider mites until they have caused severe damage and are starting to create webs, we recommend that you spray your plants thoroughly. We have a variety of sprays available:


Mighty Wash is a very effective no-nonsense spray utilizing ‘frequency-water’ technology, containing a mix of essential oils. It is quick to strike, environmentally friendly and safe to use up till harvest. Available as a ready-to-use product, Mighty Wash does not need to be diluted.


SB Plant Invigorator ranks highly amongst growers because it is concentrated, used at 10ml per litre. Effective at killing mites, this product works by suffocating them so that they can’t become resistant. SBPI also contains a mild foliar feed of nitrogen and iron, feeding the leaves at the same time as eradicating pests!


Neem Repel is a good spray for mites but does not directly kill them. It actually disrupts their feeding and reproductive activities, working most effectively as a preventative measure or in combination with another spray (our winning combination at the GroWell Sheffield Greenhouse features SBPI at 10ml per litre and Neem Repel at 20 ml per litre mixed together in the sprayer).


Nite Nite Spider Mite also suffocates and eliminates mites. It is quite viscous, and dilutes to 25ml per litre.


Spider Mite Control represents another great pest product that combines the power of essential oils with a natural ingredient designed to cause suffocation. This kills eggs as well as mites and suits smaller hobby gardeners, making up 4 litres of spray. Used at 25ml per litre.


Pyrethrum 5 EC contains natural pyrethrum – an extract from chrysanthemum flowers that is deadly on spider mites and quickly evaporates leaving minimal residues. A highly concentrated product, use only at 3-4ml per litre (2-3ml per litre for young, small or tender plants).

Pyrethrum mix

Spraying Your Plants

When spraying any product, you must ensure that you get enough coverage on the top and bottom of the leaves. Most of the spider mites and their eggs will be on the underside, so spraying from underneath is advised. Application with a hand sprayer can work well, but often the process of tilting the sprayer to get to the underside of the leaves causes it to stop firing properly. The best solution involves using the Professional Lance Sprayer, which has a lance enabling easy spraying of the whole plant. They are also ideal for getting to hard to reach spots of your grow room and hold an impressive 5L of spray solution. Highly recommended!

Code Price Qty
5 Litre Professional Lance Sprayer 3093 5 Litre Professional Lance Sprayer


If you have a larger grow room or areas that are hard to reach, or you just want an easier ride we also have a top of the range sprayer called the Nebuliser Foliar Fogger. This quality piece of kit creates a very fine mist that fogs the whole room to cover every nook and cranny. It does need to be plugged in but fogs the entire area really quickly, making even the largest of rooms an easy task. Also, because the spray is turned into a fine mist it proves to be incredibly efficient, meaning you can use less spray solution to cover the same space as a conventional sprayer. For some spray products like the Nebulizer, you will want to raise the lights to the roof or even cover them before use.


If there is a significant amount of webbing the mites can be protected by it. For severe infestations you need to spray heavily with one product, such as SPBI, to remove the webbing, then follow up with another spray to actually get at the mites!


A spray should always be administered in low light, so lift your lights up high and if you have dimmable ballasts, drop the wattage to the lowest setting. Alternatively spray once the lights are completely out, using an Active Eye Head Lamp to see where the product is being directed. During late flowering, ensure that air movement is high and humidity is low after application to enable quick drying of plant material, which helps to prevent any potential rot.

Code Price Qty
Active Eye Head Lamp 9981 Active Eye Head Lamp


Sulphur Vaporiser

Sulphur has been used in commercial horticulture for many years as a tool for tackling fungal foliage problems. Luckily the element will also deliver a mighty blow on pest communities, particularly spider mites. In raw form it’s not much use, but when the sulphur is vaporised with the Hotbox Sulfume it fumigates the growing area. This sulphur vapour disrupts how the spider mites feed and reproduce, wiping out the largest of pest populations in a short space of time. It's very safe to use whilst your plants are in the room, with the only side effect being a slight sulphur smell (akin to a fresh box of matches). Brilliant at treating areas between 2M3 and 10M3 and best to use during the dark period, simply turn ventilation fans off and fumigate the room for 3-6 hours. Note: when using the Hotbox Sulfume do not release any predators at the same time – it will kill them as well as the pests.



Natural predators of spider mites can be purchased from us to help you control spider mite populations. Phytoseiulus persimilis is a top option for clearing up low-level populations, breeding faster than spider mites if the conditions are right to eventually overpower them. The predators establish faster and eat more under a longer day, so it makes sense to use the predators during the vegetative growth cycle (18hrs of light).

Code Price Qty
Spider Mite Predators x 1000 0413 Spider Mite Predators x 1000
Spider Mite Predators x 2000 0488 Spider Mite Predators x 2000


Phytoseiulus persimilis are available in bottles of 1000 and 2000. We recommend applying 250-500 per M2 at the first signs of attack and up to 500-1000 per M2 for moderate spider mite populations. Remember, if you have an infestation you should spray beforehand to gain control of the pests then use predators.

Phytoseiulus Persimilis

Top Tip – before using your bottle of spider mite predators, lay the bottle on a flat surface for 10-15 minutes. This will distribute the predators evenly throughout the bottle (if you stand the bottle up, all the predators tend to climb to the top so you end up pouring them all over a small area). When you’re preparing to let the predators loose in your grow room, slowly rotate the bottle whilst sprinkling them over the top of the crop for a truly even spread.


As a preventative measure, you can hang small sachets on your plants containing the spider mite predator Amblyseius californicus.

Predators These predators are very cost effective and undoubtedly do the business, tolerating higher temperatures and lower humidity than Phytoseiulus persimilis – consequently making them a better choice in the summer.

Spider Mite Sachets

All you need is 1-2 sachets per plant, or 4-8 sachets per M2. Each sachet will continue to release predators for up to 6 weeks, providing great long-term protection against spider mites.


Top Tip – The slow release predator sachets will also eat other pests such as thrips larvae!


For Phytoseiulus persimilis and Amblyseius californicus to be effective, aim for a moderate temperature or 24-26oC and a relative humidity of 60-65%. This will encourage the activity and feeding of the predators whilst also slowing the spider mites down.


Top Tip - if the humidity in your grow room is low, purchasing a humidifier will help deal with spider mites. An increase in humidity lead to reduced spider mite activity and increased predator activity.


We hope this has been a useful guide. If you would like further assistance with preventing pests or ridding your grow room of an infestation, then please contact one of our growing experts by calling 0845 345 5176, leaving a message on the blog, using the chat box or visiting a GroWell shop.


This article was produced by Gareth at GroWell Sheffield

http://www.growell.co.uk/blog/wp-content/uploads/2014/04/phytoseiulus_persimilis_1_web-150x150.jpg <![CDATA[The Definitive Guide To Dealing With Spider Mites]]>
<![CDATA[pH and Conductivity in Active Hydroponics Systems]]> Fri, 11 Apr 2014 15:44:32 +0000 Nutrient Solution pH

The pH is the measure of the acidity or alkalinity of a nutrient solution. A pH value of 0 to 6.9 indicates an acidic nutrient solution, 7.1 to 14.0 can be considered more alkaline and a reading of 7 qualifies as neutral. Ideally, the pH range for hydroponics should register between 5.5 and 6.5. If you allow the pH level to fall outside of this range, it will affect your plants’ ability to utilise those nutrients.

Nutrient availabilityWhy do I need to bother with pH?

From the chart above you can see that specific elements become more and less available to plants as pH changes. If your pH is out of range and one or more of the key elements are suddenly made unavailable, this will result in poor yields, slow growth rates and nutrient deficiencies.


How do I check my pH?

When you’re in the process of producing a fresh reservoir of nutrient solution, always introduce the additives first, then nutrients and lastly check and adjust the pH.


Reading the pH can be done with a liquid pH test kit or a digital meter.

pH Test Kit The liquid pH test kit is fine if you find yourself on a budget – simply take a sample of the solution in the test tube, add a few drops of reagent and give it a shake, then match the colour of the solution against a reference chart.

Bluelab pH Pen A digital meter will provide a much more accurate level of control with less messing about – all you do is switch it on and dip the probe into the nutrient solution. If the pH shows as out of range, simply use pH down or pH up.

pH Solutions Top Tips:

- When making up a fresh batch of nutrient solution we recommend setting the pH to 6.0. This allows the nutrient concentration to increase or decrease slightly in an active hydroponic system and still be within range.

- If you have very hard water, we suggest using Nitric Acid pH Down or a combination of this and standard pH Down (phosphoric acid). Nitric acid is very aggressive and better at buffering carbonates in tap water.

- The very alkaline Shogun Silicon can be used in small amounts instead of pH Up.

Nitric Acid Silicon is a good example of an additive that you should mix with water only and then add the nutrients. Doing it the other way around results in the high pH of the Silicon reacting with the low pH of the nutrients, which causes clouding of the nutrient solution to occur. This clouding effect is nutrients precipitating out of the solution, consequently becoming unavailable to your plants. For more information see our article about incorporation of silicon into your feeds – click here

SHOGUN Silicon How do I manage my nutrient solution pH?

In active hydroponic systems the nutrient solution can be run to waste or re-circulated. Generally, run to waste is only suitable for drip irrigation and requires minimal pH management – after all as soon as you have set the pH of a new reservoir of nutrient solution it will stay the same until plants begin to drink. Most hydroponic systems re-circulate the solution and require frequent pH check and adjustments. This is due to the plants in the system actively taking up nutrients and water, which alters the pH of the solution returning to the reservoir.


How often should I check the pH?

For an active hydroponic system you should check your pH as and when you can – but the exact frequency depends on the type of system. You will find that a large volume of water in a reservoir will need less pH adjustments than a smaller volume of water. With this in mind you are able to save yourself from having to regularly adjust the pH by always keeping the reservoir as full as possible. Greater amounts of nutrient solution means the pH will take longer to change.

Nutrient Tank Tip – if you get the chance to choose the size of reservoir for your active hydroponic system, always pick the largest suitable option to ensure that the pH and conductivity drifts off target slowly.


How often should I adjust the pH?

As the pH approaches its upper parameters (6.5 maximum) you should adjust it back. It is good to allow the pH to drift up and down, as this allows the plant to access different quantities of nutrients at different set points. Setting the pH at 5.8 and allowing it to drift up to 6.6 can often provide better results than constant maintenance at 5.8.


Nutrient Solution Conductivity

Nutrient solution strength plays an important role in maintaining the health of a plant. If the nutrient solution is too strong, the leaves of the plant sometimes become leathery, curl downwards or even burn at the tips. Alternatively, a lower than desired concentration of nutrients will see the plant turn yellow, stretch and become susceptible to disease. The strength of a nutrient solution can be detected using a simple device called a conductivity meter. This indirectly measures the amount of dissolved minerals in the solution – with the more nutrient there is in the water, the higher the resulting conductivity reading.

Bluelab CF Meter What’s the difference between CF, EC and PPM?

The electrical conductivity of the nutrient solution is read by a meter and converted into units of measure, the most common values used in Hydroponics being Conductivity Factor (CF), Electrical Conductivity (EC) or Parts Per Million (PPM).


In the UK and Europe, CF and EC are most common, whereas in North America PPM appears more often. The problem with PPM is that there are different scales of conversion depending on the meter – 500 (also called TDS) and 700 – so you absolutely must know which one you’re measuring in! The difference between EC and CF is simply the decimal point (e.g. an EC of 1.0 is a CF of 10). The following chart shows the simple relationship between these values.

CF, EC and PPM What is the ideal conductivity?

As your plants grow, their demand for nutrients will change. Generally, young plants like a weaker nutrient solution and mature plants like a stronger nutrient solution. Therefore, as your plants develop gradually increase the conductivity.

CF at different stages The chart above is a general guide on the typical vales you would expect to be using at different growth stages. However, some active hydroponic growing systems require a lower conductivity than others, and environmental factors need consideration too. Read on to find out more…


Why do I need to check the conductivity?

Much like with pH, as the plants in active hydroponic systems take up water and use the nutrients, this will alter the conductivity. How much and in what direction it changes depends on the plant and the growing environment. Hungry plants tend to cause the conductivity to drop, whereas thirsty plants cause the conductivity to go up. In ideal conditions and at the right nutrient strength, as the nutrient solution is used by the plant, the conductivity remains the same.


My conductivity is increasing?!?

If your conductivity is increasing, it means the plant is using more water than nutrients. This often comes down to the grow room being too hot and/or having a low relative humidity, so by correcting these environmental problems you can stop conductivity from rising. If you are unable to reduce your temperature or increase your humidity, try keeping your conductivity lower than usual to allow for upward drift and ensure your reservoir remains topped up as much as possible.


My conductivity is decreasing?!?

If your conductivity is decreasing, it shows that the plant is taking up the nutrients from the solution so you need to increase the nutrient strength. This often happens in ideal environmental conditions where there are no excessive external demands on the plant.


Top Tips for Managing and Measuring Conductivity:

- Measure the conductivity of your tap water – this will give you a good indication of your water hardness. A CF of 0-3 is soft water, 4-5 is moderately hard, and 6 and above is considered hard.

- Subtract your tap water conductivity reading from your actual reservoir reading to get the true conductivity reading. For example if your final solution has a CF of 20 and your tap water is 5, the nutritional value of your nutrient solution is 15.

- For optimum conductivity control, use a Reverse Osmosis filter to remove all your tap water contaminant – you’ll then be able to start with a conductivity of zero.

- Active Hydroponic Systems that saturate the root zone with oxygen, such as DWC/Bubblers, require a lower conductivity than media based systems such as drip irrigation or flood and drain. This is due the efficiency at which the plants feed in DWC systems, in fact, the conductivity requirements can be as much as 25% lower than other active hydroponic systems.


This article was produced by Gareth at GroWell Sheffield

http://www.growell.co.uk/blog/wp-content/uploads/2014/04/pH-and-Conductivity-web-150x150.jpg <![CDATA[pH and Conductivity in Active Hydroponics Systems]]>
<![CDATA[How much yield are your lights losing you?]]> Thu, 06 Mar 2014 16:02:24 +0000 How bright is your bulb?

Simple fact – during the course of their working life, the light output from your grow lamps will drop in intensity.


Whether you are using high-pressure sodium lamps to produce flowers or metal halide lamps to grow and develop mother plants, regular replacement of these products is essential! But at what frequency should you carry out the changes – every 6 months, 12 months, or at the end of crops? Ultimately it comes down to how long they have been in use, since not all growers run their lamps for the same amount of time over each crop cycle.

Losing light

High Pressure Sodium Lamps

High Pressure Sodium (HPS) lamps efficiently produce light mostly in the red/orange spectrum, which is ideal for fruiting and flowering plants. Conveniently, the rate at which these products turn electricity into plant-usable light also makes them suitable during the vegetative growth stage.

A top sodium lamp You should always consider the amount of time that HPS lamps have been operated for before replacing them, and not the number of crop cycles. Why? Well every grower will inevitably manage their lamps very differently to the next. Take this following example:


Grower A

Chooses to grow 4 big plants in a 2m x 2m x 2m grow tent, with four 400W HPS grow lights. This grower has lights on for 18 hours a day over the course of a 6 week vegetative period, then flowers using a 12 hour light cycle for 10 weeks. So every complete crop cycle they will run their lamps for 1596 hours.


Vegetative Period: 18 hours x 7 days a week, then x 6 weeks = 756 hours

Flowering Period: 12 hours x 7 days a week, then x 10 weeks = 840 hours

Total = 1596 hours


Grower B

Using the same sized tent and number of 400W lights, this grower nurtures 12 smaller plants. They follow an 18-hour vegetative cycle for 2 weeks and then flower over 8 weeks. So every crop cycle they will run their lamps for 924 hours.


Vegetative Period: 18 hours x 7 days a week, then x 2 weeks = 252 hours

Flowering Period: 12 hours x 7 days a week, then x 8 weeks = 672 hours

Total = 924 hours


The example shows how two crops can have very different cycles, with each grower adopting separate strategies for using their grow lights. After 12 months of back-to-back growing, Grower A will have completed 3 crops whereas Grower B will have completed 5 crops. If they were planning on changing lamps after every crop, Grower B would be doing so almost twice as often as Grower A. Yet in reality, both of them use their lamps for a similar amount of time during the year.


Grower A

3 crops x 1596 hours = 4788 hours


Grower B

5 crops x 924 hours = 4620 hours


This reinforces the fact that to work out suitable lamp replacement times, you need to identify how many hours the lights are going to be operated.


Looking at the published data for one of the most popular horticultural high-pressure sodium lamps – the Sylvania Grolux 600W Dual Spectrum Lamp – it is noted that over the first 6000 hours of use the lumen maintenance (total light output) drops by 1% every 1000 hours of lamp use. If all other growing factors remain constant between crop cycles (environment, nutrients, growing system, plant type, etc), the amount of light is directly proportional to the crop yield.


In our example, Grower A and B will experience a light output reduction of 3-4% – which can equate to 3-4% loss in yield.

SOLAAR Lamps So how often should you change your HPS lamps? At GroWell we recommend running your lamps for a maximum of 4000-5000 hours, or around 9-12 months of continuous back-to-back growing. If you want to look at it from a slightly different angle, consider the impact on the value of your crop. When your lamps replacements are going to cost you £100 after 6 month of use, and 2% yield reduction is going to cost you £200 – it makes financial sense to change them.

Code Price Qty
250 Watt Sodium Grolux 0574 250 Watt Sodium Grolux
400 Watt Sodium Grolux 0152 400 Watt Sodium Grolux
600 Watt Sodium Grolux 0155 600 Watt Sodium Grolux


Metal Halide Lamps

Metal Halide (MH) lamps are quite different to HPS. The blue light they produce makes them more suitable for vegetative growth, or for supplementing multiple HPS lamps with extra blue light.

Metal Halide Lamp Over time, MH lamps light output decreases much faster than a HPS lamp. Where a HPS will drop 2% after 2000 hours of use, an MH lamp will drop 9%! As you can see from the graph below, the reduction at 4000 hours is 15% for MH and 4% for HPS.


So how often should you change your MH lamps? If you are using MH lighting specifically for vegetative growth and swapping to HPS lamps at the start of flowering, you need to change them every 2000-3000 hours of operation (12-18 months of back-to-back growing or 5-6 months of continuous 18 hour vegetative growth).

Code Price Qty
250 Watt Metal Halide Lamp 0363 250 Watt Metal Halide Lamp
400 Watt Metal Halide Lamp 0154 400 Watt Metal Halide Lamp
600 Watt Metal Halide Lamp 1333 600 Watt Metal Halide Lamp
1000 Watt Metal Halide Lamp 0158 1000 Watt Metal Halide Lamp


Light loss over time

This graph shows the lumen maintenance factor for both Sylvania HPS and MH lamps over 8000 hours. The BLUE line is HPS, and the RED line MH.


Sylvania Grolux High Pressure Sodium Lamp Data

Rated lumen maintenance factor at 2000 hours: 0.98

Rated lumen maintenance factor at 4000 hours: 0.96

Rated lumen maintenance factor at 6000 hours: 0.94

Rated lumen maintenance factor at 8000 hours: 0.93

Rated lumen maintenance factor at 12000 hours: 0.91

Rated lumen maintenance factor at 16000 hours: 0.90

Rated lumen maintenance factor at 20000 hours: 0.89

Rated luminous flux at 25°C (lm): 89807

Nominal average life (h): 24000


Sylvania Metal Halide Data

Rated lumen maintenance factor at 2000 hours: 0.91

Rated lumen maintenance factor at 4000 hours: 0.85

Rated lumen maintenance factor at 6000 hours: 0.80

Rated lumen maintenance factor at 8000 hours: 0.78

Rated lumen maintenance factor at 12000 hours: 0.74

Rated lumen maintenance factor at 16000 hours: 0.72

Rated lumen maintenance factor at 20000 hours: 0.69

Rated luminous flux at 25°C (lm): 30192

Nominal average life (h): 14500


All data taken from http://www.sylvania-lamps.com


Reflector Reflectivity

For HID lighting systems powering HPS or MH lamps, reflectors are very important. They help to reflect the light emitted from the top and sides of the lamp, and if of a decent quality, should provide 50% more light than using a lamp on its own.

Gavita Reflector Reflectors are made from various types of hammered aluminium, with the better ones being built out of miro aluminium – which is around 96% reflective. Over time, and through exposure to heat from the lamp, reflective surfaces slowly oxidise, resulting in a significant drop in reflectivity. Data from the Dutch lighting manufacturer GAVITA Holland shows that even high quality miro aluminium will lose approximately 1% reflectivity for every 1000 hours the light operates, and this is in a clean greenhouse environment. Unfortunately indoor grow rooms tend not to be as well maintained! Reflectors are usually positioned very closely to plants and often end up with dust and dirt, as well as stray foliar sprays, being deposited on the reflective surface. For growers using humidifiers or sulphur vaporisers, this problem is increased tremendously. If you’re using a humidifier with tap water, you will see a white dusty deposit form on most of your grow room equipment (and even the plants leaves) – this is the bicarbonates from the tap water and sadly makes reflectors not very reflective!


After 12 months in a clean grow room you can expect the reflector to loose around 5% of its original reflectivity. In a room using humidification or a sulphur vaporiser it may be as much as 10%... or more! A 10% loss in reflectivity means 5% less light (remember, reflectors should provide 50% more light than using a lamp alone) that your plants could otherwise be enjoying.


So what can you do? When using a humidifier try to use a Reverse Osmosis system to filter out the bicarbonates and generate pure water.

Reverse Osmosis System

Code Price Qty
V2 Pure 50 Reverse Osmosis System 3608 V2 Pure 50 Reverse Osmosis System


For a sulphur vaporiser, never have them burning if the lights are switched on. Cleaning your reflector with a soft microfiber cloth and a mild acidic solution helps remove some of the dust, dirt and bicarbonates from humidifiers, but unfortunately you’ll never be able to clean it back to its original state.


Commercial growers in the greenhouse sector using artificial lights take any reflectivity decrease very seriously. Even though the majority of hobby growers are on a tight budget, it is still worthwhile replacing reflectors every 12 months. The picture below shows hundreds of seemingly unblemished GAVITA Hortistar reflectors being removed from a greenhouse in Holland.

Discarded lights To maintain high reflectivity from your lighting system it’s essential to clean your reflectors regularly and consider replacing them every 12-18 months for maximum light output.

Code Price Qty
BAY6 Euro Reflector Only (IEC connection) 1083 BAY6 Euro Reflector Only (IEC connection)
Prima Klima Optomiser Reflector Only (4m IEC connection) 0659 Prima Klima Optomiser Reflector Only (4m IEC connection)
Adjust-a-Wing Enforcer Reflector only (IEC connection) 7305 Adjust-a-Wing Enforcer Reflector only (IEC connection)
Adjust-a-Wing Avenger Reflector only (IEC connection) 0953 Adjust-a-Wing Avenger Reflector only (IEC connection)
Northstar Reflector Only (4m IEC connection) 0787 Northstar Reflector Only (4m IEC connection)
Silver Parabolic Reflector only (4m IEC connection) 5211 Silver Parabolic Reflector only (4m IEC connection)

http://www.growell.co.uk/blog/wp-content/uploads/2014/03/lights-losing-yield_blog-150x150.jpg <![CDATA[How much yield are your lights losing you?]]>
<![CDATA[Optimising the IWS Flood and Drain System]]> Wed, 05 Mar 2014 16:29:45 +0000 Basic principle of the flood and drain technique

Flood and drain is an irrigation technique that fills one or more container with nutrient solution from the bottom. As the nutrient solution rises in the container(s) it forces out the old air and saturates the growing media. When the nutrient solution then drains from the container(s), fresh air is pulled down into the growing media enriching it with oxygen – vital for healthy root growth. Frequent flooding and draining of the container(s) should occur in order to optimise the available oxygen in the root zone.

Flood and Drain

Which growing media is best for a flood and drain system?

This common question has no correct answer. The growing media selected often comes down to personal preference. Good results can be achieved with many different media’s and mixes but the key features you should look for in your media are the following:

Clay Pebbles


- Low-to-medium water holding capacity (WHC)

- High air-filled porosity (AFP)


A growing media that is ideal for flood and drain without the need for anything to be added or mixed in is light weight expanded clay aggregates (LECA), commonly referred to as clay pebbles. These come with our highest recommendation for flood and drain due to the large amount of air space between the pebbles, creating a high AFP. You will also find that the porous structure absorbs and releases nutrient solution over time and can be flooded frequently with a low risk of over watering, helping keep the root zone full of lots of oxygen and fresh nutrients.


Did you know a 10L pot of dry clay pebbles can absorb up to 5L of water!? This shows just how porous they are as a growing media.


Many growers choose to mix coco with clay pebbles to increase the WHC, which allows for more time between floods and fewer floods each day. If you do this, the coco should make up 20-40% of the total volume of the growing media (we recommend 25% coco to 75% clay). Mixes containing up to 50% coco can stay saturated for long periods, undermining the basic principle of Flood and Drain.


Understanding the ‘Flood cycle’

To get the best possible results from your IWS Flood and Drain system you must endeavour to get the flood cycle right. It is made up of 3 elements:


- Flood Frequency - this is how often you flood the pot, which largely depends on the type of growing media being used and how well the plants are established

- Flood Height - this is how high the water goes up each pot. Generally we suggest that you always flood to the maximum height

- Flood Duration - this is the total time of each flood and will depend on the number of pots your systems has and the choice of growing media


Together these all play an important role in the irrigation strategy, requiring you to be very precise and accurate with your decisions for the settings.


Setting the Flood Height and Duration

This guide can be followed for all growing media, not just clay pebbles, and should provide accurate flood times and optimum results.

Start of set up When you have put the system together it’s time to get the growing media prepared. Wash the clay pebbles thoroughly to remove the dust and small particles – this can be done with tap water. Insert the root control disk copper side up and add the clay pebbles to the bottom of the pot, then add your chosen growing media on top. Only fill the pots three quarters full with your growing media at this point.

Pebbles in pots Note - no matter what growing media you use in your pots you must include 5-10cm (2-4 inches) of clay pebbles in the bottom of the inner pots. This will help prevent the bottom from holding too much water.

Preparing nutrients Now fill the reservoir with water and add nutrients to a suitable strength – ideally slightly higher (2 CF units, 0.2 EC) than your plants have been getting during propagation. Use a root stimulator for quick establishment, and finally adjust the pH to 5.5-6.5.

IWS Timer

With the nutrient solution ready, turn on the timer and start a flood cycle. Make sure the switch is set to minutes and the dial is turned all the way to the right for the longest possible flood time. The brain pot will begin to fill and so will the pots. As the pH balanced nutrient solution slowly rises in the pots the growing media will take it in - this prepares the growing media for planting.


Your aim here is for the maximum flood height to be at the same level as the top of the growing media in the pot. You should be able to see the water level rising to the surface of the growing media. Check by lightly pushing down on the media surface with the palm of your hand, thus ensuring the media isn’t floating up.

Max flooding level

If the water rises over the surface of the growing media add more media until the levels of the nutrient solution and the growing media are the same. When the brain stops filling and all the pots have the right amount of growing media and nutrient solution, leave them soaking in the nutrient solution for 30 minutes to 1 hour.


Note - If you have a slightly uneven floor, like we do at the GroWell Sheffield greenhouse, you will find that the flood height may be slightly different in each pot. By following the steps above you help to guarantee that each plant will be planted in the right position relative to the flood height in each pot. Alternatively for a perfectly level floor, the flood height should be the same in each pot.

Ready for plants

After the pre-soak period, initiate the drain cycle on the timer by turning the dial anti-clockwise to the 'cancel feed' setting. Once the drain cycle is finished, check the pH and nutrient strength in the reservoir. The pH may be a little different to before so adjust when necessary. If the pH or nutrient strength has changed dramatically, empty the reservoir and change the nutrient solution.

IWS flood timings Now you need to get a stopwatch ready to time the flood cycle. Start the flood cycle and the stopwatch (you are timing how long it takes for ALL THE POTS to fill back to the maximum flood height). As soon as the maximum flood height is reached in all the pots, stop the stopwatch and start the drain cycle.

Setting flood timer With the time recorded you can set your IWS system irrigations using an accurate flood duration. If you are using clay pebbles, add 1-2 minutes onto the time recorded on your stopwatch. This short period at the end of the flood, in which the pots stay filled, helps to saturate the clay pebbles and purge the pebbles inner core and outer shell of old nutrients. It will also allow some of the clay pebbles at the top of the pot (but not all of them) to draw up water and nutrients by capillary action.


In our 6-pot set up you can see it took just under 7 minutes to flood to maximum height, so we set our flood time to 8 minutes.


Note - it is not recommended that you hold your flood height for longer than 10 minutes. Repeatedly leaving roots completely submerged in water for too long can cause poor root function and invite disease.


If you are using a mix with coco then the time recorded is your actual flood time. You do not need to add any extra time as your growing media has a fast capillary action and holds more water than pebbles alone.



Your pots should still be around three quarters full with the growing media at the same depth as the maximum flood height.

Plants in system When it comes to putting your young plants into the system you should plant them 2-3 cm into the growing media at the maximum flood height so that during a flood cycle the flood height will reach the bottom of the propagation block. Move the plastic wrapper found around the block 2-3cm up to expose the roots – which should be healthy and clearly protruding from the bottom. Then adjust some of the pebbles, plant the block into the pot and cover back the media afterwards. The raised wrapper will now sit at the same height as the flood height.

Roots out of cube Note - if you place your young plants too deep into the pots your flood height will rise too high and saturate the propagation block causing poor initial root growth.

IWS complete

Once you are happy with the planting depth of all the plants, fill the rest of the pot with more prepared growing media.

Pebble top-up If you have been propagating plants in pots of mixed media, such as coco and pebbles, follow the same principle as described above, planting the bottom 2-3 cm of the root ball into the maximum flood height.


Setting the Flood Frequency

How often you flood the pots is determined by:


- The growing media

- The plant size and water requirements

- The environmental conditions


The Growing Media

For growing media that does not retain much water, like clay pebbles, you need to flood the pots with a high frequency. When using clay pebble and coco mixes the WHC registers higher so flood frequency will be reduced.


Clay Pebbles

Through our own trials, 8-16mm clay pebbles are best growing media for flood and drain, and we advise that you use Grodan 3” or 4” blocks for preparing your plants to grow in them. Clay pebbles require use of the IWS ‘Aqua Pots’ or the ‘Punched Pots’ – the former hold slightly less growing media than the latter but good results can be achieved with both. To prevent roots from ‘chasing’ the water through the drainpipe, a root control disk is placed in the bottom.


During a flood cycle involving clay pebbles the pots fill up with nutrient solution and drain quickly, whilst between cycles the media doesn’t hold onto large volumes of the water and feed. Consequently the flood frequency can reach a maximum of one flood every 1-2 hours when the plant is in full vigorous growth.


Your starting irrigation frequency depends on a number of factors – the size of your propagation blocks, the size of your plants and your grow room environment. Bear in mind the propagation environment will be quite different to the grow room environment, most growers find on moving plants into the main grow room that their water demand will increase due to higher temperatures and lower relative humidity (RH).


If, for example, you have a large plant in a small block that has needed watering once a day at the end of the propagation period then you should consider a flood frequency of once every 4-8 hours. If you have a small plant in a large cube that is not using much water, then 1 or 2 floods per day will suffice. It is important to make sure the block and clay pebbles do not dry out too much, or stay too wet, between irrigations.


When you can see a noticeable increase in vegetative growth, increase the frequency to once every 3-4 hours. As the plants get bigger and their need for water increases you should adjust the frequency to once every 2 hours. A lot of growers leave this as their maximum flood frequency but some large plants in a hot and dry environment with a high water demand may benefit from a flood frequency of once an hour.


Remember that during each flood routine, water and nutrients are delivered to your plant, and then on each drain of the pots oxygen is pulled into the air spaces in the root zone. Therefore when plants have become fully established within the clay pebbles, more frequent floods mean more fresh oxygen around the roots.


Note - if your plants are not well established within the clay pebbles they will not benefit from frequent floods.


In most circumstances it is only necessary to flood the pots while the lights are on. Only during warm dark periods should you consider having one night-time irrigation.



For clay pebble and coco mixes, you can use the IWS ‘Culture Pots’ or the ‘Punch Pots’. The bottom 2-4 cm of the pot should be filled with just clay pebbles, the rest of it is then free to accommodate the combination of growing media. Again, the Culture Pots hold slightly less media than the Punched Pots but good result are obtainable with both.


The key to application of coco in flood and drain systems is not to over-water. If you are using 20-40% coco, for the first 1-2 weeks after planting – the establishment time – the pots will need irrigating a maximum of once a day, ideally in the middle of your light period. Some growers find they get better results by hand watering from the top of the pot every 1-2 days over the first week and go onto using the flood and drain irrigation cycle once they know the roots are well established and ready for regular irrigations. This is an excellent approach for establishing your plants, but understandably sometimes proves to be impractical for growers with larger systems or for growers who run their light cycle during the night.


After the plants are established and vigorous vegetative growth has started, the plants water demand will increase. Around this time check the moisture level of your coco pebble mix before the irrigation or towards the end of your light cycle – if it is drying you should increase your frequency to 2 times a day. The first and second irrigation should be equally spaced, e.g. if you want to run an 18 hour light cycle your irrigations would commence at the 6 and 12 hour mark.


These 2 irrigations are, in most cases, as much as they need, but plants that have a high water demand may require irrigating 3 times a day during peak growth. An important phrase to consider when irrigating your coco coir and clay pebble mix is ‘transpiration before irrigation’, which means to wait for your plants to start using the water in the growing media before irrigating. Taking this into account, you should have your first irrigation at least 1-2 hours after the lights turn on.


Environmental considerations

As with any hydroponic system, your nutrient strength and irrigation must reflect your grow room environment.


For example, if the growing media is clay pebbles and during summer the room runs at 28°C with an RH of 45%, these hot and dry conditions will cause the plant to use more water and less nutrient. Consequently the nutrient strength needs to be set lower than usual to account for the nutrient strength rising in the reservoir. In these conditions the pots should be flooded once an hour.


In the same room during winter, imagine the room runs at 26°C with an RH of 60%. These more favourable conditions won’t put environmental pressures on the plants, meaning higher nutrient strengths are suitable and flood frequencies can be reduced to once every 2-3 hours. It is therefore extremely important to consider the effect that your grow room environment has on your plants and adjust your feeding strategy accordingly.


IWS Flood and Drain

IWS Flood and Drain System Maintenance


Avoiding root blockages

Because the flood and drain system fills and empties through the same tube, roots growing out of the pot can sometimes cause blockages in the pipework. To avoid this, always use the copper root control disks provided. You can also purchase IWS Pot Filters that screw onto the inside of the outer pot and prevent roots growing into the pipes. If you are able to get in amongst your plants, routinely turn the inner pot round 45° in the same direction every 2-3 days, which helps make sure roots stay away from the tube and contributes towards a more even growth pattern.


Checking for root blockages

Suspect your pots or pipework are blocked up? Then you can soon find out by quickly flooding the pot, pouring 5-8 Litres of nutrient solution into the top of it. If the solution drains away freely you’ve got nothing to worry about, if the solution sits there and takes a long time to drain you most likely have a blockage.


Note - this technique only works well with clay pebbles. If your pot is blocked you should remove the inner pot and check the inlet/outlet tube for roots or debris.


Minimising system problems

Most of the common issues come about through failure to keep a clean system. You must make sure the float switches in the brain pot do not become dirty or clogged up with any growing media. Each time you refill the reservoir a quick rinse with fresh water over the switches will help prevent problems. Over time some sediment and/or debris may collect in the reservoir or brain pot, remove or clean it immediately.


Common problems and solutions



My system fills but doesn’t drain?



This is usually because of a problem with the pump in the brain pot. A pump that is vibrating but not pumping will either be air locked or blocked. Simply twist it so the inlet faces up – the release of air bubbles and sound of the pump starting to work means the problem is fixed. If this issue often occurs inspect the fill tube and make sure water is not being directed onto or near the pump. To rectify an issue here, turn the tube outlet around to pour solution down the side of the brain pot instead of allowing it to splash the surface of the water.


If the pump is vibrating in the brain pot and does not release any air bubbles when turned, it may be blocked. You should turn the power off, remove the front off the case from the Maxijet 1000 and inspect the impeller and inlet. Remove any debris and replace.


If the pump in the brain pot dos not vibrate or work properly then check the bottom float switch. As long as the product is clean and hasn’t been forced open you can contact GroWell returns/repairs department or IWS directly for help, as you’re probably dealing with a faulty pump, timer unit or float switch.



My system won’t stop filling/my pots are over flowing?



Here the problem typically comes down to a siphoning effect that allows the pump in the reservoir to keep filling the brain pot at a reduced rate when the power switches off. Check the anti-siphon valve in the reservoir is not underwater or blocked – instead it should be near the top of the reservoir and able to take air into the pipe when the pump is off to stop the water from flowing. If you do not have an anti-siphon valve you should alternatively find a small hole drilled in the pipework coming up from the pump at the top of the reservoir. Check that this is not blocked.


For a pump that still fails to siphon and carries on filling the brain pot at full power, you may be looking at a faulty top float switch in the brain pot. Ensure the float switch is clean and free from debris. If in good condition, then you should contact the GroWell returns/repairs department or IWS directly as you may have developed a faulty timer unit or float switch.



Some of my pots are over-flooding?



When you have an uneven floor and some or all of the pots are lower than the brain pot, you will get some over-filling. Put simply, the pots must be sat on the same level as the brain pot – this is essential to how the system works.



Why is the EC/CF rising rapidly in the reservoir?



Nutrient strength normally rises slowly in the reservoir as plants generally use more water than nutrients. If your temperatures are high (above 28ºC) and relative humidity is constantly low (below 50%), the rise in nutrient strength will be accelerated. These environmental conditions can cause a quick rise in nutrient strength between feeds because the nutrients will accumulate in the pots. Add more water to the reservoir to dilute the nutrient strength and consider reducing the nutrient strength by 0.2-0.4 EC units (2-4CF).


Rapidly rising EC/CF may also be a sign that your flood frequency is too low and the growing media gets too much time to dry out between flood cycles. Consider increasing the flood frequency.



Why is the pH rising rapidly in the reservoir?



pH tends to rise slowly in the reservoir during normal nutrient uptake by the plants. If you are finding that the pH climbs rapidly and you have to add lots of pH down it is normally due to the clay pebbles. Sometimes failing to wash the media properly and no pre-treatment of it with nutrient solution at the correct pH can lead to rises at the early vegetative growth stage. However, the pH will stabilize given time. Try not to add lots of pH down – opt to use a mixture of nitric acid and phosphoric acid, which will help the balance of minerals in the nutrient solution.



Why is the pH dropping rapidly in the reservoir?



pH drop can sometimes be a normal occurrence during the transitional phase from vegetative growth to flowering/fruiting. Adjusting back up with potassium hydroxide (ph Up) or potassium silicate (silicon) is recommended.


If the pH drops rapidly you may have a problem triggered by over-watering. A higher than necessary flood frequency and constantly saturated growing media depletes oxygen levels, leading to a fall in pH. Over-watering increases plant susceptibility to root disease and can ultimately cause root death – check that your growing media does not remain wet for too long between irrigations. If this is an issue, consider reducing the flood frequency.


We hope you found this article useful. For any further advice on the IWS system, or anything growing related, please don’t hesitate to contact us.


This article was produced by Gareth at GroWell Sheffield

http://www.growell.co.uk/blog/wp-content/uploads/2014/03/Pic_X-web-150x150.jpg <![CDATA[Optimising the IWS Flood and Drain System]]>
<![CDATA[Pruning Plants For Improved Ripening]]> Mon, 03 Mar 2014 12:35:33 +0000 Traditional gardeners find that the constant warm temperatures and long sunny days of summer are ideal for the maturation process, whereas the lower level of heat and light associated with subsequent autumn days fails to provide what is really required. At this point in time plants often don’t have the energy necessary to ripen their fruit.


Indoor gardeners are typically able to grow plants all year round and tend to experience no major issues when it comes to ripening. However, the speed at which fruits become available to harvest can usually be accelerated by actively focusing all of the plant’s efforts on the job at hand.


For both sets of growers, if the plants could do with an extra push to help them ripen their fruits it makes sense to carry out a little bit of a trim!

Overgrown Chilli Wilma

These ‘Bishops Hat’ chilli plants growing on a Wilma 8 System desperately need some attention. The growth has not been supported and it’s covered in green pods buried mostly within the canopy. Time to grab the Greenblade Trimming Scissors!


A few hours later and what a difference! Most of the lower stems and leaves without any fruit have been removed to improve airflow throughout the plants, which really helps to prevent fungal problems. The upper stems were cut back to the nearest pods, removing the new growth and small immature pods that will not get enough time to grow to full size this season.

Trimmed Chilli Wilma

The upper stems are also now supported in an upright position using Yo-Yo’s, allowing the pods and leaves to bask in sunlight. The removal of a lot of the foliage also improves light penetration through the plants.

Code Price Qty
Lockable Yellow Plant Yo-Yo - pack of 4 0541 Lockable Yellow Plant Yo-Yo - pack of 4
Lockable Yellow Plant Yo-Yo - pack of 10 0547 Lockable Yellow Plant Yo-Yo - pack of 10

Overall, the plants have gone from being part of an overcrowded environment where they shaded each other out, to more of an open set up that affords the pods and leaves better access to light through the plants – consequently improving ripening. Also the removal of the leaves and stems works to significantly shock and stress the plants, giving them a startling wake up call to hurry up and get on with ripening the seeds and pods to guarantee the survival of their offspring.

Ripening Chilli Wilma

One week later and you can see the effect that the pruning has had! Lots of pods are now fully ripe and ready for harvest, with many more on their way!

Overgrown Chilli NFTThe same transformation was also carried out on the monster Yellow Rocoto plant growing in an NFT Gro-Tank. Since doing so the pods have been cropping extremely well.

Fruiting Chilli NFT

Finally, just a word of warning – don’t be tempted to take off excessive amounts of foliage. Stripping away too many leaves can leave you in a worse situation, where the plant is unable to photosynthesise and create the sugars it needs to perform key plant functions like ripening pods.


Furthermore if you’re using an unheated greenhouse and only relying on sunlight for growth, problems with slow ripening plants during late summer, autumn and winter can be remedied by installing grow lights to provide additional daylight on dull days and extend the day length. Heating the greenhouse with a KlimaHeat Heater to keep day and night time temperatures up will also have a big impact on the ripening processes of plants.

Code Price Qty
80 Watt KlimaHeat Tubular Grow Room Heater 0611 80 Watt KlimaHeat Tubular Grow Room Heater


This article was produced by Gareth at GroWell Sheffield

http://www.growell.co.uk/blog/wp-content/uploads/2014/03/Wilma3-web-150x150.jpg <![CDATA[Pruning Plants For Improved Ripening]]>
<![CDATA[Growing In Coco – Getting The Basics Right!]]> Tue, 18 Feb 2014 09:50:51 +0000 Pre-soaking the media

We recommend pre-soaking your coco media before planting on, applying a three-quarter to full-strength feed until run off appears.


Coco is a unique media capable of storing a lot of nutrient salts. It should therefore always be your goal to ensure you give plants a thorough watering. This sounds like common sense but actually catches quite a lot of people out!

pH checking coco


Measuring your nutrient

To get the best from your plants, you must measure and monitor the pH and EC/cF of the nutrient solution (with a suitable pH meter and EC/cF meter) – both prior to application and also as run-off. Ideally, the pH should range between 5.2 and 6.7. The EC/cF, which refers to the strength of the nutrient, generally needs to sit somewhere between 1.0/10 and 2.0/20, depending on where your plants are at in the growth cycle.


To check the nutrient levels within your coco media, do the following:

1.) Take a measuring jug and fill it with 150mls of deionised water

2.) Remove samples of coco from as many places as possible in your slabs/pots

3.) Add the samples to the deionised water until it reaches the 250mls mark

4.) Mix and allow to settle for at least two hours

5.) Mix again and measure the pH

6.) Filter and measure the EC/cF


If the pH and EC/cF readings are not inline with your target figures, you will either need to reduce the strength of your nutrients by adding water or increase the strength of your nutrients by adding more concentrate.


Tip – checking the EC/cF and pH levels of your run off also helps to build a sound irrigation strategy. The EC/cF of the run off solution should be between 0-15% higher than the EC/cF of the solution that you initially applied. This is because you are basically washing through stored nutrient in the media that has built up over time from previous feeds.


Moisture of coco media

To achieve a higher level of air within your coco media (good for drainage and root growth), you should make sure it is not too moist. An easy way to determine whether your coco media contains the appropriate amount of moisture is to squeeze the media. When the media has been squeezed, the moisture should disappear between your fingers. If water runs out of the media – it’s too wet, if no moisture appears – it is time to water again.


Lifting your pots/slabs and making assumptions based on the weight of them is an alternative method for checking moisture. Pots/slabs that are very heavy tend to contain larger amounts of water, and as they get lighter and lighter you’d naturally expect to find less and less liquid.



Hand feed during the establishment/propagation period to maximise root growth. This should be done by the half way rule – i.e. once the saturated weight has reduced by half, saturate the growing media to 30-40% run off and continue this until roots appear in the drainage holes.

Watering by hand For hand-fed plants, repeat this process throughout the growing period. If you do not run any nutrient to drain as outlined above, make sure that you only apply water every third watering during the winter months (when grow rooms are cooler) and every other watering in the summer (when grow rooms are warmer).


For active irrigation systems, fully grown plants using coco need irrigating between 3 and 8 times a day for 2-5 minutes, or with 4-6 litres per square metre depending on plant size, plant density and environmental temperature. In general, coco requires approximately 20-40 % run off each day to keep the root zone at a set EC/cF level.

Drip feedingTip - one of the great benefits of growing in coco is that you can use the incredibly powerful boosters designed for hydroponics and truly maximise your yields. See our rundown of the products considered most effective at increasing the overall number and size of your fruits by clicking here!

http://www.growell.co.uk/blog/wp-content/uploads/2014/02/cocopH-150x150.jpg <![CDATA[Growing In Coco – Getting The Basics Right!]]>
<![CDATA[Top Tips For Boosting Your Yields – Hydroponic Additives And Stimulants]]> Wed, 12 Feb 2014 11:07:30 +0000 If you are looking for ways to give your plants an extra little push at certain points throughout the growth cycle and ultimately want to increase final yields, this is the right place to come! Over the course of the next few articles every single nook and cranny of the grow room will be examined to find the products and techniques that genuinely help to improve crop performance and results.


Recommended additivesBefore you begin your own personal search for yield utopia, first make sure that you’ve got a good grip on the basics. At the bare minimum, you need to be able to do the following:


1.)  Exert a decent level of control over key aspects of the growing environment, with particular emphasis on the effective management of your extraction and light systems. This will allow you to establish desirable temperature and humidity settings that are relatively simple to adjust when deemed necessary in order to keep plants healthy.


2.)  Recognise and fulfil the specific feed-related requirements of your plants – which include the creation of suitable strength nutrient solutions and maintenance of optimum pH levels, cF levels and liquid temperatures.


3.)  Competently guide your plants through each stage of the growth cycle, starting by rooting cuttings/seedlings for propagation and ending with the removal of fruits at



As soon as you possess the core indoor growing skills, it’s time to explore what can be done to raise the number and size of fruits your plants produce. The first “Top Tips For Boosting Yields” article concentrates on a selection of additives and stimulants that promise to deliver exceptional returns.


Supply The Ammo – Flowering Boosters

The most obvious option for maximising yields involves incorporating at least one flowering stimulant into the feed program during the latter half of a crop. Although the majority of nutrient packages tend to include a bloom feed with a ratio of elements tailored towards the fruiting demands of plants, it is really easy to turbo-charge them furthermore and step up to a whole new level.


There are no shortages of additives for enhancing flowering performance, but you will discover that some products do a slightly different job than others.

PK Warrior 9-18PK boosters like SHOGUN PK Warrior, Canna PK 13/14 and Vita Link Buddy form a particular segment, providing a rich supply of readily available potassium and phosphorous – the fundamental raw ingredients your plants need to develop fruit and flowers.


Then you have active bloom stimulators such as SHOGUN Sumo Boost and Canna Boost Accelerator, which forcibly push plants to use as much of the previously mentioned essential flowering elements as possible.

Sumo BoostDue to the positive relationship that exists between these two distinctive types of products, combining a PK additive and bloom stimulator is seriously recommended and will definitely lead to increased yields.


More Roots Equals More Fruits – Rooting Boosters

It’s important to remember that every single action you take over the entire course of a crop has a bearing on yields, not just those directly associated with the flowering cycle. Nurturing roots to establish a solid foundation for growth and a comprehensive system for absorbing and transporting water and nutrients is typically a primary focus at the beginning of plant life, yet the process should be continued beyond this period.

Roots and fruits Over the first couple of weeks of vegetative growth the use of an additive specifically designed to trigger initial root development like B’cuzz Root Stimulator will help to build a large and healthy root system.


Applying Hygrozyme at the same time and continuing with it late into flowering effectively works to maintain the base of the plant to the highest standard, whereby enzymes complete a number of ongoing advantageous tasks – e.g. breaking down old roots to allow room for new ones. Beneficial biological products such as AkTRIvator Trichoderma and Vita Link Bio-Pac also do a similar job and are worth checking out.

HygrozymeStarting out on the right foot and quickly creating a widespread network of strong roots is crucial in terms of yields because at the later stages plants are then able to efficiently uptake more of the ‘fuel’ (water and nutrients) required to drive flowering functions and can also support the weight of heavier fruits. Also, plants that have a well developed healthy root system will be better equipped to deal with abiotic (environmental) inadequacies that can cause increased water usage, such as brief periods of high temperature or low humidity.


Invest In ‘Silicon Enhancements’

A stronger, altogether tougher plant is going to yield more than a weaker alternative – no doubt about it. Exposing your plants to Silicon, either as a root feed or foliar application, thickens cell walls to bring about a whole host of advantages.

SHOGUN SiliconSuddenly insects and disease will find it harder to penetrate the more durable surface of plants whilst environmental factors such as wind and heat become less of a concern due to the increased stability and reinforced structure. So Silicon actually helps reduce the impact of significant threats on your end gains. Ultimate protectionMeanwhile the efficiency of internal functions also improves and bulked up stems and leaves can be seen to accommodate greater quantities of fruits that are also bigger in size – which means you’ll get to enjoy huge yields!

Protective layers Honourable Mentions

To reiterate the earlier point, almost everything you feed your plants has implications on yields, it’s just that some things do more than others – with many of the ‘heavy hitters’ being listed above. There are, however, a few more products worthy of recognition.

SuperThrive Vitamins/Hormones additives: provide stress relief and acts as a general health booster, e.g. SuperThrive and Vita Link Bio-Plus.

Vita Link Bio-Plus Calcium and Magnesium additives: encourage increased PK consumption, revive ailing plants, balance nutrient absorption and stimulate vegetative growth, e.g. Bloom CALMAG and SHOGUN CalMag (the latter includes extra Iron – an element that produces a 'greening up' effect).

SHOGUN CalMag Late flowering feeds: used in place of your regular nutrients during the last two weeks before harvest to ripen fruits and boost their final size and weight, e.g. General Hydroponics Ripen and SHOGUN Dragon Force.

Dragon Force Don’t Push Too Hard

The temptation to throw every type of additive at your plants in huge quantities is understandable considering the many different and exciting types of product available – yet you’ve got to fight these feelings if they ever arise!


The old adage “too much of a good thing can make you sick” applies to plants as well as humans, which means you must be careful with your mix of nutrients and stimulants. By all means experiment, of course! Remember to play it safe though, taking note of concentrations and manufacturer usage guides. On top of this, only introduce one new product at a time – any more than that amount and how will you know what has/hasn’t worked?


Speaking of application, did you know that altering nutrient strength and feed times at critical times can actually have an influence on yields? Find out more about it here.


Conveniently your plants will show you clear signs if they are being over-fed or under-fed, through discolouration of leaves and stems (note: lower leaves may naturally turn yellow and fall off in the flowering stage as energy is directed at the production of flowers). Read up on what to look out for with regards to primary macro-nutrients here.


We hope this information has been insightful. Look out for future articles on the equipment and growing techniques that can also help to boost yields!

http://www.growell.co.uk/blog/wp-content/uploads/2014/02/AdditivesStimulants_02-150x150.jpg <![CDATA[Top Tips For Boosting Your Yields – Hydroponic Additives And Stimulants]]>
<![CDATA[Secrets of Successful Propagation: Time To Transplant!]]> Mon, 10 Feb 2014 11:37:32 +0000 The seedlings are really rocking along nicely now (23rd of December 2013), with most of them showing healthy white roots protruding from the starter plugs. Guess it’s time to transplant!


At this point in the propagation process don’t be tempted to relocate the seedlings from the propagator unless you have a humid environment of around 70% RH in your growing area – anything lower and they will begin to wilt. Ideally, continue to keep them in the propagator until there are signs of healthy and well-developed root systems, then they can be hardened off and prepared for life outside of the propagator. The large Vitopod Propagator is extendable in height, which will continue to prove ideal for accommodation of the plants as they grow bigger and become more established.

Chillies in jiffy's

The Purple Jalapenos and Peppadew seedlings growing in jiffy plugs have come an awful long way and look ready for potting on. These will be going into small 100cm pots of Canna Coco Professional Plus. Currently the seedlings are being fed Vita Link Plant Start at an EC of 0.6-0.8/ cF 6-8.

Protruding roots

Once you see roots protruding from the jiffy plug like this they can be potted on.

Transplanting cubes

All the seedlings in the Grodan rockwool cuttings seed cubes are also growing at a good rate and now need moving into larger transplanting cubes. Rockwool always requires some pre-treatment before use, so these transplanting cubes were soaked for 10-15 minutes in water at a pH of 5.5, then flushed through with a nutrient solution containing Vita Link Plant Start at an EC of 1.2/cF 12 and pH of 6. Shake off the excess nutrient solution then insert the seedling. Job done!


Vita Link Plant Start gets our top recommendation for propagation. It’s a great complete nutrient solution for establishing cuttings and seedlings and has been specifically created for the task, as opposed to using a weak strength adult feed. We won’t delve into the science too much here (check the product page for full details), but basically Vita Link Plant Start contains a whole host of essential micro-elements including Boron, Calcium, Iron, Manganese, Copper and Zinc, each and every one at exactly the right level for young, developing plants. With plenty of Vitamin B1 in there as well to aid stress relief during cloning, not to mention the beneficial Humic and Fulvic acids that encourage the uptake and movement of nutrients through the roots, it promises to support and accelerate early vegetative growth.

Finished transplanting

Most of the seedlings in rockwool plugs are now potted on, can’t wait to see how they develop!


Check out the previous articles in this mini-series:

Secrets Of Successful Propagation: A Closer Look At Rooting Media

Secrets Of Successful Propagation: An Early Start And An Exciting Innovation

http://www.growell.co.uk/blog/wp-content/uploads/2014/02/Pic-03-web-150x150.jpg <![CDATA[Secrets of Successful Propagation: Time To Transplant!]]>
<![CDATA[Secrets Of Successful Propagation: A Closer Look At Rooting Media]]> Wed, 22 Jan 2014 12:17:20 +0000 As predicted, at around the 2-week stage (17th of December 2013) a lot of the seeds have sprouted. The bottom heat provided by the Vitopod Heated Propagators certainly seems to work a treat, with most varieties showing 90-100% germination rate.

Code Price Qty
Grodan Small Cuttings Seed Cubes x 48 0847 Grodan Small Cuttings Seed Cubes x 48
Grodan Large Cuttings Seed Cubes x 24 0848 Grodan Large Cuttings Seed Cubes x 24


At this point you have probably noticed the use of a wide range of propagation media, and maybe wondered; “what is the best growing medium for seeds?” Well, it really comes down to your personal preference because they all need treating and maintaining slightly differently. Root Riot Cubes are quicker to dry than Grodan Rockwool Cubes, so you have to water them a bit more frequently. Jiffy Plugs will give you a good all-round performance, but do tend to retain more water than both Rockwool and Root Riot Cubes – meaning you must be careful not to over water them in the early days.


You can see below that the Purple Jalapeno and Peppadew seedlings are growing at a good rate in the Jiffy Plugs. Since the surface of the peat is noticeably starting to dry, these are about ready to be watered again. A very dilute nutrient solution with an EC of 0.6 / cF 6, pH 6.0 should do the trick nicely! Check out our articles on measuring and adjusting cF and pH levels if you're unsure of how to do these important tasks.

Code Price Qty
Jiffy Plug (each) 3879 Jiffy Plug (each)
Seramis - 10 Litres 0669 Seramis - 10 Litres


The Aji Fantasy seedlings (shown below) popped up extremely quickly in the Root Riots. This particular variety is a tall, fast-growing Capsicum annum – therefore it doesn’t come as a surprise to see that the seedlings are already shooting skywards!

Code Price Qty
Fleximix Root Riot Organic Starter Cubes x 24 0006 Fleximix Root Riot Organic Starter Cubes x 24
Fleximix Root Riot Organic Starter Cubes loose refills x 100 3102 Fleximix Root Riot Organic Starter Cubes loose refills x 100


The next milestone will be when the germinated seedlings are ready for transplanting into bigger rockwool cubes or pots of coco. By then, you’d expect all of the seedlings to have developed a healthy enough root system for ‘potting-on’, but only the best ones need taking forward.

Stay tuned to see how the chillies develop!

Check out the previous articles in this mini-series:

Secrets Of Successful Propagation: Time To Transplant!

Secrets Of Successful Propagation: An Early Start And An Exciting Innovation


This article was written by Gareth at GroWell Sheffield

http://www.growell.co.uk/blog/wp-content/uploads/2014/01/Pic-03-web1-150x150.jpg <![CDATA[Secrets Of Successful Propagation: A Closer Look At Rooting Media]]>
<![CDATA[Producing Awesome Chillies With An AutoPot System]]> Thu, 12 Dec 2013 15:30:37 +0000 It’s been a great year for growing chillies in the GroWell Sheffield greenhouse! Even the ones that were planted late on have produced fantastic results, including an interesting and unusual variety called Friars Hat.

Friars Hat – also known as Bishops Hat and Barlett’s Bonnet – originate from Brazil and are a member of the Baccatum species of chilli. The fruit have a very unique shape, with three or four flat protrusions kind of resembling the rim of a hat, whilst the level of heat generated tends to be relatively mild, closely matching that of the more common Jalapeno pepper.

Seeds at Sheffield were sown back in early April 2013, meaning most plants had become established by mid-May ready for moving into the main AutoPot System.

So what led to the decision to use an AutoPot 4-Plant System? Here are some of the contributing factors:

- Nutrient solution is delivered to the plants when they need it courtesy of the ingenious AquaValve

- Any growing medium will work effectively in the pots

- No electricity is required, saving money on the energy bill

- The system proves to be very low maintenance

- The modular design allows for use in different sizes and shapes of room

- If needed, the system can easily be expanded with an extension kit

To get the plants from seed to system, the following steps had to be taken:

1.)  Plants were propagated in Jiffy Pellets

2.)  These were then transplanted into 10cm Square Pots with Canna Coco Professional Plus Medium

3.)  Next the plants got transplanted into 6.5 Litre Square Pots

4.)  Finally they ended up being transplanted into the AutoPot 15 Litre Square Pots

Now you may ask why all of this potting on was done? Well, put simply a plant should always be planted into a pot that suits its size. Consequently, planting a small seedling or cutting straight into a large pot can easily lead to over-watering and poor establishment due to the media holding a lot more water than the plant is able to consume.

Once located in the 15 Litre pots, the plants received feeds via a watering can for a few weeks to allow necessary time for the development of a deep and extensive root system. However as soon as their need for daily top ups became apparent, the system was set up and switched on.

You will notice here that the standard 47 Litre tank belonging to the AutoPot 4-Plant System has been replaced with a 100 Litre Space Sava Water Butt – this is for no other reason than convenience. If you’re managing numerous growing systems, like staff at the GroWell Sheffield greenhouse, it just helps if you can reduce how often you need to replenish the nutrient solution.

Code Price Qty
Space Sava Water Butt - 100 Litres 2233 Space Sava Water Butt - 100 Litres
Space Sava Water Butt Stand 2234 Space Sava Water Butt Stand


That said, throughout the season the level of nutrient solution in the reservoir has been changed to suit the growing environment. During the summer when temperatures are high and the humidity is low in the greenhouse, nutrient levels for the Canna Coco feed are measured with a Bluelab (cF) Nutrient Truncheon and set to a cF of 15 (EC 1.5). Over the past few months though the cF has been increased with the decreasing average temperature and increasing humidity – which is up to a more usual cF of 22.

Code Price Qty
Bluelab (NZH) Nutrient (cF) Truncheon 0121 Bluelab (NZH) Nutrient (cF) Truncheon


Since the AutoPot System delivers nutrients to each of the four bottom trays, in which a pot and plant stand, and then passively wicks them up into the growing media, it’s important to be on the lookout for potential issues relating to over-fertilisation. Simply continuing to run a high conductivity while the temperatures and/or humidity are also high will lead to an accumulation of nutrients in the growing media, which often stops plants from being able to properly function.

If you have any concerns that extreme environmental conditions are going to cause plants to become over-fertilised, every 2-3 weeks do the following:

1.)  Wait until the reservoir is empty so that the plants obviously need feeding

2.)  Create the next batch of nutrient solution at half the strength of the previous one

3.)  Hand feed your plants, pouring the nutrient solution through the top of each pot and emptying the runoff from the bottom tray until 50% of it has been collected (i.e. if you’re feeding each plant 3 Litres of nutrient solution, 1.5 Litres should be collected as runoff)

4.)  Fill the reservoir with a nutrient solution that is back up to full strength

5.)  The plants will have had a chance to recover and are now ready for normal feeds again


If the above sounds like too much hard work, every third time you fill your reservoir simply use a half strength nutrient solution.

By late October a sensational crop of chillies was ready to harvest, all grown with minimum fuss using an AutoPot 4-Plant System!

For more expert advice on AutoPot Systems, please get in touch! Speak to us via chat over the main site, call our technical team hotline on 0845 345 5176 or pop into one of our eight stores located in London, the Midlands, Sheffield and Bristol.

Code Price Qty
AutoPot 4-Plant System 1839 AutoPot 4-Plant System


This article was written by Gareth at GroWell Sheffield

http://www.growell.co.uk/blog/wp-content/uploads/2013/12/fh2-150x150.jpg <![CDATA[Producing Awesome Chillies With An AutoPot System]]>
<![CDATA[Correctly Incorporating Silicon Into Your Feeds]]> Mon, 09 Dec 2013 16:52:30 +0000 Following on from our detailed look at the advantages of feeding silicon to your plants, this practical guide aims to display the most effective method of mixing up a nutrient solution that includes a good silicon additive.


The Plan

Two separate batches of nutrient solution are going to be prepared, with one showing you what happens when silicon is used correctly to the manufacturer’s recommendations (this is now referred to as the 'left bucket') and the other demonstrating how things will appear if you try and add it like a normal booster (this is now referred to as the 'right bucket'). The process for each of these will go as follows:


LEFT Bucket                                                                 RIGHT Bucket

1.) Dechlorinate water                                                  1.) Dechlorinate water

2.) Add silicon                                                               2.) Add silicon

3.) Adjust pH level to around 7                                     3.) Add nutrients

4.) Add nutrients                                                           4.) Adjust pH level to preferred target

5.) Adjust pH level to preferred target


The Equipment

Both feeds are for plants in the vegetative stage. They will include exactly the same amounts of the following products:

- 15ml of Vita Link Max Grow A and B

- 10ml of SHOGUN Silicon


On top of these, there is also the need for some pH adjustment equipment and vinyl gloves – a sensible precaution when handling aggressive liquids.

Code Price Qty
Disposable Vinyl Gloves - Box of 20 0552 Disposable Vinyl Gloves - Box of 20
Disposable Vinyl Gloves - Box of 100 1047 Disposable Vinyl Gloves - Box of 100


The Process

Two buckets each containing 10 litres of water were left to stand for several hours before adding any of the feed or silicon stimulant. This allows the chlorine to dissipate and the water to reach ambient temperatures.

Code Price Qty
20 Litre Budget Black Bucket 0493 20 Litre Budget Black Bucket


The first stage is always to introduce the silicon, at a rate of 1ml per litre – so 10ml was added to each bucket and mixed in.

Code Price Qty
SHOGUN Silicon - 250mls 2321 SHOGUN Silicon - 250mls
SHOGUN Silicon - 1 litre 2322 SHOGUN Silicon - 1 litre
SHOGUN Silicon - 5 litre 2323 SHOGUN Silicon - 5 litre


Code Price Qty
Nutrient Measuring Syringe - 20mls 0615 Nutrient Measuring Syringe - 20mls


A quick check of the pH levels of the mixtures using a pH Meter comes in at 9.3 for the left bucket and 9.2 for the right bucket.

Code Price Qty
Accuread pH Meter 7520 Accuread pH Meter


Now this is the crucial stage that sees the only variance between the two batches – one capable of making all the difference to your nutrient solution. The combination of water and silicon in the left bucket will be pH adjusted from 9.3 to around 7 before adding the nutrient whereas the bucket on the right receives no such treatment. As always you reduce the pH level by adding a few drops of pH down to a jug of water and then slowly pour it into the solution until you reach the target figure.

Code Price Qty
pH Down - 250mls 0130 pH Down - 250mls


Code Price Qty
Nutrient Measuring Syringe - 10mls 0432 Nutrient Measuring Syringe - 10mls


Code Price Qty
1 Litre Measuring Jug 1546 1 Litre Measuring Jug


With the pH level in the left bucket now registering 6.8, both buckets are ready for the nutrient to be added. In this scenario a mid-vegetative solution is created, introducing 15ml of parts A and B of Vita Link Max Grow.

Code Price Qty
Vita Link Max Grow 2 Litre (soft water) 1450 Vita Link Max Grow 2 Litre (soft water)
Vita Link Max Grow 2 Litre (hard water) 1444 Vita Link Max Grow 2 Litre (hard water)
Vita Link Max Bloom 2 Litre (soft water) 1453 Vita Link Max Bloom 2 Litre (soft water)
Vita Link Max Bloom 2 Litre (hard water) 1447 Vita Link Max Bloom 2 Litre (hard water)


Next you would normally adjust the pH levels of the nutrient solutions to sit between 6 and 7, obviously depending on the species of plant being grown. For chillies you ideally need to hit just below 6.5 – although as long as it goes no higher than 7 the plant will have easy access to the nutrients.


What immediately stands out is that the pH level for the bucket on the left has not changed from the pre nutrient reading of 6.8. Silicon does help buffer the pH levels, but this still represents a pretty astounding result – especially when you consider that the bucket on the right, also containing silicon, saw a drop of 1.7 from 9.2 to 7.5.

The silicon is most stable and easy to integrate into the solution at around the pH 7 level. Consequently you need to adjust the pH level to the desired starting point by gradually adding the diluted pH down solution until the target is reached.

Both nutrient solutions are now sitting at a pH level of 6.3 and ready to be applied to a system.



The point of this exercise was two-fold. Firstly, it set out to show you that the extra step of reducing the pH of the solution once the silicon has been added leads to optimum performance and better integration of the silicon into the solution. Secondly, there was a need to demonstrate what can happen when the correct method of mixing the water, silicon and nutrients is not followed. With regards to the latter point, sometimes the result of adding the silicon at the end of the process of creating a feed is a cloudy solution.

Here nutrient has essentially precipitated out of the solution, failing to integrate with the solution in a way that is of benefit to the plant. If your solution does become cloudy, the plant will simply not be able to take up the silicon. The best thing to do is start again, this time adjusting the pH level before adding the nutrient. Whilst it may only seem like a little step, it can make all the difference!


So to incorporate silicon into your feeds in the most effective manner, do the following:

1.) Dechlorinate water (by letting a bucket of it stand for 24 hours)

2.) Add silicon (at a rate of 1ml per litre)

3.) Adjust pH level to around 7

4.) Add nutrients

5.) Adjust pH level to preferred target


To remind yourself of the benefits of feeding silicon to plants, click here!

Code Price Qty
SHOGUN Silicon - 250mls 2321 SHOGUN Silicon - 250mls
SHOGUN Silicon - 1 litre 2322 SHOGUN Silicon - 1 litre
SHOGUN Silicon - 5 litre 2323 SHOGUN Silicon - 5 litre

http://www.growell.co.uk/blog/wp-content/uploads/2013/12/siliconSG-150x150.jpg <![CDATA[Correctly Incorporating Silicon Into Your Feeds]]>
<![CDATA[Food For Thought: Silicon Enhancements]]> Thu, 14 Nov 2013 14:49:27 +0000 Overview

The addition of silicon basically enhances the physical structure of your plants by actively thickening cell walls and the bonds between cells. Over time plants will become stronger and stronger, often to the extent that they can maintain a sturdy upright position without having to rely on support devices like yo-yo’s and netting (though we recommend always putting up these products). When you further consider that the element in question boosts plant growth rates and size, the ability to stand completely unaided represents quite an impressive feat!


Toughened up stems, branches and leaves present invading insects and diseases with an incredible barrier to try and penetrate, a ‘shield’ of sorts that plants can use cleverly to counter live attacks. Rather than simply continuing to reinforce every single part of the external structure, a plant under pressure will direct fresh intake of the element to vulnerable areas to strengthen these at critical times. Talk about a responsive design!

In general silicon-enriched plants tend to develop a greater tolerance of the environment and negative aspects associated with it, from the destabilizing rushes of air your pedestal fan can generate to the uncomfortable levels of heat brought about by the summer sun. Put bluntly, being in better shape improves the odds that your plants will have of overcoming issues relating to cold, heat, humidity and wind.


Striving to produce stronger plants through application of silicon clearly leads to a wide array of benefits – and not all of these have been mentioned above! The following article is a comprehensive review of silicon, which pleasingly identifies positive effects on yields! Keep reading to find out more…

Code Price Qty
SHOGUN Silicon - 250mls 2321 SHOGUN Silicon - 250mls
SHOGUN Silicon - 1 litre 2322 SHOGUN Silicon - 1 litre
SHOGUN Silicon - 5 litre 2323 SHOGUN Silicon - 5 litre


What is Silicon?

Silicon is a natural element, one of many ‘key ingredients’ that help to create everything in the universe. You find it on this planet as sand (silicate dioxide) and sheet silicates (compounds containing silicon, oxygen and an additional metal or mineral) – which form over 90% of the earth’s crust. Interestingly only oxygen can be found here in greater supply! Silicon is extracted from sheet silicates as a monosilicic acid, a process that makes it available to plants.

Silicon and Plant Nutrition

Despite being one of the most common natural elements around, silicon is not essential to the development of plants – they can go without it and still grow to a satisfying standard. Yet as you will come to see, this approach overlooks some serious potential gains! Consequently you should seek to discover if your plants are currently accessing silicon via their growing medium and/or feeds, how they benefit from the element and what needs to be done if you want to increase the availability of it.


Silicon and Soil Grown Plants

Silicon already exists in a lot of soil as silicates but the actual amount available to plants (i.e. soluble) is typically under half of what they are able to use. You can add further doses of silicon by using a stimulant like SHOGUN Silicon as a root feed and/or foliar spray, the advantages of which have been outlined further down the page in ‘The Benefits of Silicon’.


Silicon and Hydroponically Grown Plants

The inert media associated with hydroponics (and coco) and silicon-free nature of the related nutrients means that plants grown using this method have no natural exposure to the element. Introducing it to a hydroponics set up can be done via the application of a stimulant like SHOGUN Silicon, as a root feed and/or foliar spray. The reasons you should do this are now explained.


The Benefits Of Silicon

When a plant takes in silicon via the roots or leaves, it has 24 hours to choose whether to put the element between cell walls or in the cell walls themselves (as silica) of growing shoots. These deposits set in place and then act like cement, making cells thicker and therefore stronger, ultimately increasing the structural integrity of your plants.

Many of the benefits associated with silicon stem from the fact that plants become stronger as a result of absorbing the element.


Stronger plants = more stable plants

Establishing a solid foundation for your plants on which to build future growth is the main aim when dealing with cuttings and seedlings and application of silicon as a foliar spray during the propagation stage can only help to toughen them up.

Including silicon in feeds (only foliar sprays for soil users) throughout the vegetative growth stage will serve to significantly strengthen the stem of plants, still letting them bend and flex with the movement of the air but crucially ensuring that they are a lot less likely to snap or topple over.

The larger, thicker, lush green branches that are developed before flowering really play an important role once your crop reaches the final 8 weeks or so, since the plants can then hold bigger, heavier fruits, and lots of them, encouraging the move towards maximum yields.

Stronger plants = more efficient plants

All areas of a plant benefit from silicon – including roots, stems, branches and leaves – and in most cases you’ll be able to notice the difference it has made because of how pronounced the bulking up effect is on them. But this is by no means just for show! Plants naturally become more efficient too.


Adding silicon helps build a bigger, stronger Phloem and Xylem in the stem structure, which facilitates the movement of increased quantities of nutrients and water, with these essential elements being absorbed and transported at a quicker speed for larger and faster overall plant growth and development. The more robust nature of the stem and improved efficiency on offer improves the access a plant has to some elements that are more difficult to uptake and move around than others (e.g. calcium). It also gives plants a greater tolerance to stressful situations (e.g. where there is a lack of water and increase in the level of heat), letting them overcome adversity and keep on functioning properly.

The plant’s ability to convert light into energy through the process of photosynthesis improves as a result of consuming silicon. By actively stimulating the production of dense, wide-spanning, rich green foliage, you increase the total surface area of the plant that is exposed to sunlight, CO2 and water, the concentration of chlorophyll per unit of leaf tissue and the efficiency of use of available CO2. Think of it like expanding a factory floor, extending the space for increased productivity and providing all the tools and materials to achieve this goal. A stronger, sturdier plant is also more likely to maintain an effective position for maximising the rate of photosynthesis – which eventually leads to greater yields.

Stronger plants = more resilient plants

You can’t stop bugs and diseases from being a threat to your plants, so what’s the next best thing? To limit the damage they are able to cause in your grow room. The ideal solution would be one that creates a physical barrier around your plants, blocking out alien invaders – exactly the type of protection that silicon delivers when it is applied!

Silicon bolsters up cell walls and the bonds between them, meaning plants can prevent a particular pest or disease from getting a foothold and spreading. With adequate preparation and maintenance of the thick outer coating that is created by plants (you must keep on applying a silicon additive over the course of a crop), bugs stand little chance of breaking through (including Spider Mites and Aphids) and diseases won’t fare much better either – whether it be powdery mildew, pythium (root rot) or botrytis (bud rot). In the case of an actual attack, the plant knows how to direct fresh supplies of silicon to the susceptible spots to immediately alleviate the issue. That’s an intelligent natural defense system for you!

Looking beyond insects and disease, the extra strength that plants generate as a result of taking in silicon also makes them more resilient to the affects of weather, humidity and temperature extremes. For example, temperatures above 30oC tend to bring the metabolic process of turning food into energy to a halt because the required water is lost through transpiration quicker than it can be replaced. But with silicon deposits strengthening the cell wall of a plant, the transportation components inside the stem are less likely to collapse, instead facilitating the movement of water at higher temperatures, reducing the level of transpiration and allowing for normal plant functions to continue.

In addition to the advantages that silicon will give your plants by strengthening them, there is the positive effect it has on the uptake and balance of other elements…


Silicon helps to establish and maintain a good balance of elements

An interesting point to remember with regards to nutrient management concerns the differing quantities of each element that your plants require and the relationships between some of these elements. With this in mind, it should be noted that silicon actually influences the uptake and management of certain nutrients and can even help correct deficiencies!


As was discussed in the article ‘Food for Thought – A Brief Insight Into Plant Nutrition’, there are some elements that your plants use in large amounts (Nitrogen, Phosphorous and Potassium), some that they use in slightly smaller amounts (Calcium, Magnesium, Sulphur and Silicon) and some that they use in only tiny amounts (e.g. Sodium). If too much or too little of an element is in the system a plant typically begins to suffer and displays signs of a toxicity or deficiency – like the discolouration of leaves.


Applying silicon will have the positive knock-on effect of encouraging your plants to absorb more zinc (important for growth and photosynthesis), calcium (important for growth, enzyme activity, metabolism and uptake) and nitrogen in soil (essential for vegetative growth and most plant functions). On top of this it balances the uptake of phosphorous (essential for flower and fruit formation), ensuring toxic levels of the element are avoided. Likewise by competing for uptake against certain elements that are only required in small amounts (e.g. aluminium, manganese and iron), the presence of silicon actually stops unhealthy and excessive nutrient consumption.


Introducing silicon into the feeds of indoor grown plants

By now it should be apparent that there are some serious benefits up for grabs if you choose to incorporate silicon into the diet plan of your plants. Of course, after you make the decision to do this there is then the question of how you can most effectively get it into their systems…


Hydro, Coco and Soil growers can apply silicon via products like SHOGUN Silicon, as a root feed and/or foliar spray. Both of these additives provide silicon in the soluble and highly accessible form of potassium silicate, which gives you the added bonus of also providing a good source of potassium – a vital element for flowering. Since you really need to be using silicon on a regular basis to establish an effective barrier, we recommend carrying out root feeds with the occasional foliar spray for an extra boost when needed.


Bottled base nutrients do not contain silicon because it requires a high pH level to stay in a soluble form, a setting that would cause undesirable reactions (e.g. nutrient lockout and then deficiency) with the other featured elements. Therefore to include silicon in your feeds, it must be the first thing you add to your water and thoroughly mix in – only then can the base nutrients follow.


The limited timeframe a plant has to deposit the silicon in its system means that a constant supply of small amounts of the element is required during propagation, vegetative growth and flowering. This guarantees that all new growth benefits from the positive effects of silicon.

Code Price Qty
SHOGUN Silicon - 250mls 2321 SHOGUN Silicon - 250mls
SHOGUN Silicon - 1 litre 2322 SHOGUN Silicon - 1 litre
SHOGUN Silicon - 5 litre 2323 SHOGUN Silicon - 5 litre

http://www.growell.co.uk/blog/wp-content/uploads/2013/11/silicon-enhancments-150x150.jpg <![CDATA[Food For Thought: Silicon Enhancements]]>
<![CDATA[Forget Godzilla... have you seen the NFT Chilli Monster!?]]> Tue, 15 Oct 2013 14:59:22 +0000 When this beast was planted onto a NFT Gro-Tank 205 GTi back in April nobody expected it to get so huge! Talk about demonstrating the power of hydroponics!

Code Price Qty
NFT Gro-Tank 205 GTi (71cm x 40cm - 20 Litre capacity) 0330 NFT Gro-Tank 205 GTi (71cm x 40cm - 20 Litre capacity)


Believe it or not, this plant has actually been hacked back on three occasions in an attempt to control its rampant growth! Now standing at a meagre 6ft tall and just as wide, this Yellow Rocoto (capsicum pubescens) is dripping with ripe pods. A slightly unusual variety, rocoto chillies are round and contain larger than normal black seed and have soft hairy leaves. The heat level is up there with the scotch bonnets, weighing in at around 100,000-300,000 Scoville heat units - perfect for curries, marinades and making hot sauce.


Maintaining this hydroponic set up doesn't take much effort at all. Simply ensure the irrigation pump is on a low flow, and leave it running 24/7 – the way a true NFT system should be run.


The Reflex Black and White Reflective Sheeting over the tank helps to reflect light and heat away from the root zone to keep it cool and dark - a top tip if you want to enjoy a highly productive root zone.

Code Price Qty
Reflex Black/White Reflective Sheeting - 10 metres 1292 Reflex Black/White Reflective Sheeting - 10 metres


cF and pH checks are made daily, with adjustments proving necessary every 1-3 days as and when the solution needs rebalancing. Complete reservoir change outs are done every 2 weeks.

As you can see here, the root mat on this NFT system is really thick! This only further demonstrates the true power and effectiveness of NFT for growing healthy and productive plants.


Vital Stats:

  • System: NFT 205 GTi
  • Nutrients: Vita Link Max Bloom (cF 25, pH 6.0)
  • Irrigation Strategy: continuous irrigation, 24/7
  • Top up tank: 100L containing nutrient solution at cF 15, pH 5.5


At this time of year the nutrient solution is maintained at a higher cF level of 25. However, during the summer months it will be dropped back to an upper cF of 18. Why? Well, throughout the summer months the air temperature of the greenhouse is higher and has a lower relative humidity. This causes an elevated transpiration rate, inducing the plant to increase uptake of water and leave the nutrients in solution. Overall this leads to the nutrient solution cF rising as the water is removed by the plant. By running a lower cF, you are ensuring that the nutrient levels do not become too high for the plant at times of increased water uptake. For cooler months, where light level is lower and humidity is higher, the plants transpiration rate is much lower, and so does not take up as much nutrient solution. This means that the small amount of nutrient solution it does take up needs to have a high nutrient concentration to maintain healthy growth. Seasonal tweaks like this are very important to ensure good year round production.


Fancy trying a Yellow Rocoto Chilli? Come along to our Sheffield store where you can pick a pod to take home and try. If you save the seeds, you'll be able to grow these on yourself next season.

http://www.growell.co.uk/blog/wp-content/uploads/2013/10/nft_chilli_monster_1-150x150.jpg <![CDATA[Forget Godzilla... have you seen the NFT Chilli Monster!?]]>
<![CDATA[Winter is coming...]]> Mon, 14 Oct 2013 16:20:23 +0000 After harvesting the final fruits and then removing plants from your grow room, the tendency is to try and get the next lot in as soon as possible to maintain a steady stream of produce. However, taking a little time to make sure everything is in place can pay dividends – especially at this time of the year.

Grow room clear out

Inevitably your grow tent will need to be cleaned, and we’re not just talking about a little sweep here and there. A thorough clean will remove any debris that is present, and more importantly, also helps eradicate any pest residue. Even if you didn’t suffer from a bug problem during your most recent crop, we suggest carrying out this process.

Grow room fumer

With the bulk of the debris removed, the first step is to blitz any visibly remaining and/or potentially hidden bugs using a Fortefog Fumer. This is especially important for larger grow rooms and an extremely effective means of eradicating any lingering bugs. Ensure all plants and indeed people are removed from the area before lighting the fumer, then seal up the grow room and leave for a good few hours.


Code Price Qty
Midi Fortefog 'P' Fumer - 11g 0479 Midi Fortefog 'P' Fumer - 11g


Grow room cleaning agent

RoomClean has been specially designed to leave your grow room looking sparkling clean, as is required for the housing of new plants and equipment, and comes available in a ready-to-use spray if you want to get straight to it. Remove every item of equipment and clean them separately (especially in smaller set ups) and make sure you hit all the corners and crevices that may conceal pests and collections of debris. Similarly ducting ports also need some attention and should be securely closed off afterwards.


Code Price Qty
RoomClean ready to use Sprayer - 750mls 1499 RoomClean ready to use Sprayer - 750mls


Using RoomClean


Now the tent is clean you have one last thing to do to give yourself the best possible chance of a successful harvest and that involves administering a preventative spray of Neem Repel. Mix 20ml per litre with warm water into a spray gun and liberally spray the inside and outside of the tent concentrating on those previously mentioned corners and ducting ports. Neem Repel not only acts as a pest repellent but can also be very effective against mildew and blackspots, making it an essential product in our eyes. Such preventions are especially important at this time of year because falling outside temperatures encourage pests to move indoors and into a nice warm environment like a grow room. Applying Neem Repel would deter them from choosing your one!


Code Price Qty
Neem Repel Concentrate - 250mls 1110 Neem Repel Concentrate - 250mls

Out of stock

Budget 750ml  Spray Gun 3654 Budget 750ml Spray Gun



These simple steps only take a few hours but help you to create a nice clean environment ready for the next batch of plants, providing peace of mind that every effort has been made to prevent any future problems.

Cleaned grow tent

Preparations to protect your plants against the conditions that winter brings and re-introduce cleaned equipment to the grow room can now begin.

Measuring temperatures

The first and perhaps most important tool in the battle against the cold is the Accuread Temperature & Humidity Meter, which will let you know the current, highest and lowest temperatures and humidity recorded. Closely monitoring these factors and resetting the meter every day to give you current and accurate readings proves 100% worthwhile, since the more information you have available the better equipped you will be at making changes and maintaining control.


Code Price Qty
Accuread Temperature and Humidity Meter 0876 Accuread Temperature and Humidity Meter


If your grow room is on a concrete floor, say in a garage, conservatory or cellar, an upturned Garland tray on the floor of the tent covered by the catchment tray will ensure that the plants are not sat directly on a cold surface, reducing the risk of them suffering from any ill effects attributed to the harsher conditions. Just the few centimetres gap provided by the tray can make a massive difference.

Protective garland tray

Keep plants off floor


Code Price Qty
Metre Square Garland Work Tray (100cm x 100cm) 5871 Metre Square Garland Work Tray (100cm x 100cm)
1.2 Metre Square Garland Tray (120cm x 120cm) 1482 1.2 Metre Square Garland Tray (120cm x 120cm)


A source of heat is obviously recommended for during the winter, with the 80 Watt KlimaHeat Tubular Grow Room Heater proving to be both gentle and incredibly efficient. Designed to take the edge off the cold during the lights off period, simply use alongside a timer (to provide optimum levels of control) and an Accuread Temperature & Humidity Meter (to monitor conditions).

A KlimaHeat Heater


Code Price Qty
80 Watt KlimaHeat Tubular Grow Room Heater 0611 80 Watt KlimaHeat Tubular Grow Room Heater


The next aspect to consider is your extraction system. Often during the winter a lot of growers will just turn the fan down, but the purpose of the extraction system goes beyond temperature control – it also provides the air exchange that aids plant health in an indoor environment and helps control the humidity. Turning down the fan stops you from providing adequate air exchange and allows the humidity to rise, which brings about all sorts of problems. In a set up with just an extraction fan and no intake fan, the air exchange needs to be maintained. In larger set ups where an intake fan is also used, a RAM fan speed control unit will do a fantastic job at controlling the temperature and air flow.


Code Price Qty
RAM Air-Pro Fan Speed Controller 5461 RAM Air-Pro Fan Speed Controller


Using the Klimaheat Heater during the lights off period should help maintain temperatures and reduce the need to turn down the fan to the extent where it could cause further issues.


Whist on the subject of extraction systems, when using an intake fan during the winter months, you cannot really afford to be bringing in air from the outside. Introducing cold air directly into the grow room will shock the plants and significantly reduce performance. Instead, introduce air from another room indoors.


Once you have everything in place it is worth monitoring temperatures for a couple of days before moving the plants into the grow room – this will give you an opportunity to program the timer for the KlimaHeat so that a stable temperatures can be found and maintained. You may discover, for example, that the unit does not need operating when the lights are on. Close monitoring of the temperatures over these few days is key. Obviously the environment will change as soon as the plants are introduced and begin to develop, but initially stabilising the temperatures helps get them off to a good start.


If temperatures are still too low, especially in the depths of winter, an oil filled radiator can be used outside of the grow room to establish and maintain optimum conditions. Avoid fan heaters wherever possible because the hot air given out by these units tends to drastically dry the foliage and again impede performance.

Yellow sticky traps

With the addition of some yellow sticky insect traps to alert you of any bugs seeking entry into your warm indoor environment, everything has been done to protect the grow room itself from the cold temperatures.


Code Price Qty
Horti-Shield Yellow Sticky Insect Traps 1926 Horti-Shield Yellow Sticky Insect Traps


Nevertheless there are still a few extra steps you can take if you’re using an active hydroponics system like an IWS Bubbler or NFT Gro-Tank. Soil or coco offers some protection for the roots, but in active systems the roots are more exposed and therefore more vulnerable to extremes of temperature. Just as you need to monitor nutrients temperature in the summer and use chillers where required, the opposite is equally important in winter. The plants will not take up nutrients effectively when the nutrients are cold, consequently having a negative impact upon their ability to perform. There is a range of Heavy Duty Nutrient Heaters available to keep the temperatures at the right levels, and a handy Accuread Digital Nutrient Thermometer to inform you about the temperatures of your nutrients.


Code Price Qty
Accuread Digital Nutrient Thermometer 1213 Accuread Digital Nutrient Thermometer
Heavy Duty Hydor Nutrient Heater 50 Watt 0179 Heavy Duty Hydor Nutrient Heater 50 Watt
Heavy Duty Hydor Nutrient Heater 150 Watt 0224 Heavy Duty Hydor Nutrient Heater 150 Watt
Heavy Duty Hydor Nutrient Heater 300 Watt 0225 Heavy Duty Hydor Nutrient Heater 300 Watt



As always the most important factor in the battle against cold temperatures has been saved until last, and that is vigilance. Regular monitoring of the information provided by your grow room equipment and your plants performance proves crucial during the winter months. If you leave your grow room unattended for a few days or a week, the cold may creep in and stunt your plants growth, but if you follow our guidelines and keep a close eye on things a successful harvest is possible even in the middle of the winter.


Top tips.

1 – keep a close eye on temperatures in your grow room.

2 – keep pots and systems off cold floors.

3 – do not draw in air from outside in the winter months

4 – do not use fan heaters to heat your grow room

5 – use nutrient heaters and monitors for optimum performance

http://www.growell.co.uk/blog/wp-content/uploads/2013/10/lilywithshow_blog-150x150.jpg <![CDATA[Winter is coming...]]>
<![CDATA[Vita Link Max - Feed Chart]]> Fri, 04 Oct 2013 15:55:28 +0000 Vita Link Max is the nutrient of choice for many hydroponics growers, having been designed to provide plants with the essential elements for growth in a remarkably effective and efficient manner. It contains a unique, highly accessible supply of phosphorous (phosphites) that helps fight off fungal attacks and disease during vegetative growth to maintain strong and healthy plants, whilst in flowering everything then goes into increasing the size of final fruits.


To begin as you mean to go on with Vita Link Max, we recommend downloading and viewing our feed chart by clicking here.


This will enable you to familiarise yourself with how the product works over the course of a crop and still promises good results come harvest time. After you've gained a bit of experience, you should try tweaking things a little here and there to see if gains can be made in terms of yields.

Code Price Qty
Vita Link Max Grow 2 Litre (soft water) 1450 Vita Link Max Grow 2 Litre (soft water)
Vita Link Max Bloom 2 Litre (soft water) 1453 Vita Link Max Bloom 2 Litre (soft water)
Vita Link Max Grow 10 Litre (soft water) 1451 Vita Link Max Grow 10 Litre (soft water)
Vita Link Max Bloom 10 Litre (soft water) 1454 Vita Link Max Bloom 10 Litre (soft water)
Vita Link Max Grow 20 Litre (soft water) 1476 Vita Link Max Grow 20 Litre (soft water)
Vita Link Max Bloom 20 Litre (soft water) 1477 Vita Link Max Bloom 20 Litre (soft water)
Vita Link Max Grow 2 Litre (hard water) 1444 Vita Link Max Grow 2 Litre (hard water)
Vita Link Max Bloom 2 Litre (hard water) 1447 Vita Link Max Bloom 2 Litre (hard water)
Vita Link Max Grow 10 Litre (hard water) 1445 Vita Link Max Grow 10 Litre (hard water)
Vita Link Max Bloom 10 Litre (hard water) 1448 Vita Link Max Bloom 10 Litre (hard water)
Vita Link Max Grow 20 Litre (hard water) 1478 Vita Link Max Grow 20 Litre (hard water)
Vita Link Max Bloom 20 Litre (hard water) 1479 Vita Link Max Bloom 20 Litre (hard water)

http://www.growell.co.uk/blog/wp-content/uploads/2013/10/vitalinkmax-blog-150x150.jpg <![CDATA[Vita Link Max - Feed Chart]]>