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Building Your First Telos LED Grow Room

Building Your First Telos LED Grow Room

Alex Grady

Are you thinking about setting up your first Telos LED grow room? Nice move! We’ve only ever received positive customer feedback about the Pro lighting range and it remains one of our all-time favourites!

This article is designed to give beginner growers and new users of Telos products a step by step guide to creating a complete grow room. We’ve tried to cover absolutely everything that you’d want to know!

How much space do I need for a Telos LED Grow Light?

There’s a Telos LED light configuration for every shape and size of room. Generally speaking, coverage areas are as follows:

Coverage Area Model
60cm x 60cm to 90cm x 90cm


100cm x 100cm to 120cm x 120cm

TELOS 10 Pro

Where can I set up a Telos LED grow room?

Lofts, garages, spare rooms and greenhouses are all good locations for a Telos LED grow room.

As the units only give off a really small amount of heat and this is via convection rather than radiation (i.e. the heat rises up to the top of your room/tent, not down over your plants), you can use them in much tighter spaces than conventional HPS lights.

To achieve the best results we recommend investing in a BudBox Pro White Grow Tent, which gives you complete control over the whole environment and lots of handy features. Most notably, you’ll find that the white interior is highly diffusive for even coverage and excellent PAR reflectivity.

When operating on more of a budget, the silver-lined BAY6 Tents also perform well and represent superb value for money.

Ensure your grow room has a suitable power source. Multiple Telos LED Lights can actually be linked together with inexpensive accessories, all running through one plug socket and no contactor! You’ll just need 1x H-Connector and 1x Link Cable for every extra unit you intend to add to the original. This works for up to 10x Telos 6 Pro and 6x Telos 10 Pro.

What height should I hang my Telos LED Grow Light?

Adjusting the height of your Telos LED Light is required over the course of the plant lifecycle to optimise distribution and intensity. We suggest these guidelines:

Growth Stage Height Above Plant Tops






Rope ratchets make it easy to quickly alter the hanging height.

In rooms/tents that are big enough (1m x 1m and upwards), consider having additional LED lights, CDM lights or HPS lights ready to use alongside your main Telos unit(s) when temperatures drop during the winter since this will help introduce more heat.

How long should I run my Telos LED Grow Light each day?

To mimic sunlight and the outdoor seasons, get your Telos LED Light(s) on a timer and run them accordingly:

Growth Stage On/Off Duration


18 hours on, 6 hours off


12 hours on, 12 hours off

The Heavy Duty Lighting Timer is ideal for one-light Telos LED grow rooms.

How much air should I extract for a Telos LED Light?

With Telos LED Lights running cooler than HPS alternatives, there isn’t the need to extract air to the same extent. Typically, this means you should be able to run a slightly smaller (and less expensive!) extraction system compared to an HPS setup. Using a temperature controlled fan controller will also reduce speeds and energy consumption when possible – a key feature during the colder months of winter, where less air exchange is recommended. In both cases, EC fan equipment represents the most flexible and cost-effective option.

The calculation for selecting a suitable size of extractor fan is relatively simple:

Step 1: Check you’re using the right Telos LED Light for the chosen area

E.g. 1x Telos 10 Pro for a 1.2m x 1.2m x 2m Tent

Step 2: Calculate the total area of your grow room/tent (length x width x height)

E.g. 1.2 x 1.2 x 2 = 2.88m³

Step 3: Work out the volume of air you need to exchange per hour (total area x 60)

E.g. 2.88 x 60 = 172.8

Step 4: Factor in the use of a carbon filter and ducting by adding 25%

E.g. 172.8 x 1.25 = 216m³/hour

Step 5: Opt for an extraction system that can move the required amount air

E.g. 125mm RVK (220m³/hour) or 125mm RAM (248-284m³/hour)

Step 6: Consider using a fan speed controller to reduce extraction rates at certain times

E.g. Control Freak Single Fan Controller

What Are The Air Intake Requirements For A Telos LED Grow Room?

Opening the vents on smaller grow tents is adequate for air intake. Bigger setups should bring in cool outside air during the summer (helpful when you’re battling against high temperatures – although less of a concern for users of Telos LED Lights, which run 3°C lower than HPS) and warm CO2-rich air from other indoor areas during the winter.

How Do I Need To Mix The Air For My Telos LED Grow Light?

Thoroughly mixing the air in your grow room is good practice all year round. In winter, when the cold conditions can threaten a crop, it’s important to direct the convected heat produced by your Telos LED Light(s) down towards plants. A DiffuseAir does this job better than anything else, and if you’re adding extra CO2, it’ll help evenly disperse the growth gas too.

Should I Add CO2 To My Telos LED Grow Room?

Adding CO2 can increase yields by a huge 20-30%. You can really reap the rewards of introducing extra CO2 in a Telos LED grow room because the lower extraction rates increase the time for CO2 enrichment to take effect. In other words, any CO2 you add will be in contact with plants for a longer period of time before it then gets extracted away. New and/or small scale growers should consider using bagged gas (e.g. Exhale) or canister gas (e.g. TNB The Enhancer), whilst bigger and more seasoned growers are better suited to propane gas and bottled gas setups.

What Temperature And Humidity Should I Target With A Telos LED Grow Light?

The suggested daytime temperature in a Telos LED grow room is 24-28°C. At night, you should aim for 22-23°C.

To hit these targets during winter, a heater will almost certainly be required – ideally with a thermostat. Check out the KlimaHeat Electric Grow Room Heater, which is designed to keep conditions in a 2°C range of your selected temperature. When linked up to the digital thermostat it’ll typically operate for short periods of time, delivering effective bursts of heat only when needed, saving you loads of money compared to an oil-filled radiator.

In terms of humidity, there are huge benefits that can be enjoyed by creating different conditions at different stages of growth (consider getting a humidifier and dehumidifier to do so). Here are the optimum ranges:

Growth Stage Relative Humidity

70-80% RH


65-75% RH


45-65% RH

Even at higher humidity levels, there’s no reason to worry about your Telos LED Grow Light – both the 10 Pro and 6 Pro models are rated IP66 water-resistant.

You must monitor grow room conditions to work out when to extract more or less air, turn heaters on or off and turn humidifiers on or off. Equip yourself with an Accuread Temperature & Humidity Meter at the bare minimum. For access to stored data on a really useful app, maybe consider upgrading to an AirComfort Temperature & Humidity Sensor.

What Growing System And Nutrients Should I Use With A Telos LED Light?

You can successfully raise plants using your preferred products and growing method in a Telos LED setup – soil, coco and hydro users will all smash it!

Plants don’t over-transpire due to the lack of radiant heat, so they can cope with a higher nutrient strength. And, due to the intense nature of the light coming from the unit(s) – which is either 2.4 μmol per Watt (6 Pro) or 2.5 μmol per Watt (10 Pro) – the nutritional needs and, more importantly, the growth potential of your plants will likely increase!

Just keep an eye on your EC in active hydro systems and use this to direct your EC levels. In passive or hand watering systems, keep checking leaves, looking for any slight burning of the tips. If you start seeing signs of this, reduce your nutrient strength by a couple of points.

Any questions? Start a chat or call 0333 003 22 96 and we’ll do our best to help.

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