CO2: The Do's and Dont's (Q&A with Donnie from MyCO2)

Want big yields? Better get your CO₂ level right. We’ve thrown all the questions we can think of at Donnie from MyCO2. Check out his answers to find out the what’s, when’s why’s and how’s of CO₂ 

Meet Donnie from MyCO2. He knows a thing or two about CO₂, and he's kindly answered some questions for us.

What are the best CO₂ levels for each stage of growth?

My answer to this one is half science and half personal opinion, truth be told.

Science shows that plants grown with optimal CO₂ (1200 ppm) throughout their entire life cycle grow faster, stronger, and produce a far better harvest.

There are gardeners who supplement CO₂ during their grow cycle to speed up the growth rate so they can switch to the flowering cycle sooner.

There are also gardeners who claim their plants use CO₂ more efficiently in bloom, especially when they are starved, or only supplied with fresh air during vegetative growth.

The idea is that supplying less CO₂ than is desired (say 600 ppm of CO₂), forces the stoma opening to expand and work harder to absorb more CO₂. Then, when 1200 ppm of carbon dioxide is provided during bloom, the open stoma is better equipped to absorb more CO₂ compared to a plant that has been made lazy, having been given a good amount of CO₂ the entire time.

Kind of like if you starve a human, they eat their food quickly and eat every last bite once fed, but someone who has a feast for a king at every meal will pick at everything and not necessarily clear their plate.

Does your target CO₂ level vary during different seasons or climates?

Not really. Anything more than 1200 ppm is a waste, and anything below is less than what your plants can handle.

Some science shows that plants grown in augmented CO₂ levels perform better if also in elevated temperatures, typically between 80^oF and 90^oF.

The problem is, these temperatures are too high. Temperatures like that can increase the risk of grow room problems.

This doesn’t mean that CO₂ is useless in lower temperatures, say 65^oF to 78^oF, a range most gardeners stay within. It just means that a measurable increase in production is realized when high CO₂ is coupled with higher than usual temps.

What are the benefits of having optimum CO₂ levels?

Thousands of laboratory and field studies from around the world have conclusively shown that elevated CO₂ levels stimulate plant productivity, growth, harvest potential, and crop quality. It’s also proven to have water-conserving and stress-alleviating benefits.

Even a small bump in CO₂, like say a 300 ppm increases herbaceous plant biomass by 25 to 55%.

There’s a great YouTube video that shows this benefit in time-lapse. This isn’t a video produced by my company, so don’t think we’re being biased...this is science!!

How would you recommend testing grow room CO₂ levels?

You can’t go wrong with a digital CO₂ monitor or even a cheap disposable CO₂ test kit. Use them to test the air at plant canopy level and lower – remember, CO₂ has a tendency to fall as it’s heavier then air.

This will give gardeners a visible calculation of how well their MyCO2 bag is producing in their specific growing environment and whether or not they need more MyCO2 boxes.

It’s also a good idea to take detailed notes of every growing cycle and compare the results of CO₂ grows to non CO₂ grows across the board.

Over time you’ll quickly realize the incredible benefits this invisible chemical adds to your crop production.

Are there any consequences for a CO₂ level that’s too low? Are there any early warning signs in plants?

Yes. CO₂ is absolutely vital for plants.

Without it, plants won’t be able to photosynthesize – where plants use CO₂, H₂O and sunlight energy to make sugars such as monosaccharide (glucose) and disaccharide (sucrose).

Low CO₂ levels weaken the cell structures of the plants and give them an off colour. Like humans who are starved of oxygen, plants who are starved of CO₂ become sick and eventually die.

Many new gardeners, having learned from another experienced gardener the amazing benefits of closed system gardening, forget how important CO₂ is.

They set up a room, put in the plants but forget to add CO₂. Plants quickly convert all the available CO₂ and begin to literally suffocate.

What’s the best way for a grower to work out how many CO₂ bags they need?

We recommend one MyCO2 Bloom per 4x4 area or per 4x4 grow tent as a minimum.

Two MyCO2 Bloom in a 4x4 area is best, and can be extrapolated to larger growing areas using that unit of measure.

Even if you don’t use as many as we recommend, you’ll still notice a difference when you grow with MyCO2 bags than when you grow without.

MyCO2 Bags are self-activated, which is a big plus – how does this work?

The way it works is simple.

The live culture is grown in a sterile environment on sterilized medium, which is placed into the bag after the substrate has been sterilized and cooled.

All of this is done in a biology laboratory, by well trained lab technicians.

The culture continues to grow in the top section of the bag until the clip is finally removed by an end customer and the live culture is introduced to the sterile substrate below.

After about 5 to 10 days of recovery, a bell curve of byproducts is created as a result of the mycelium decomposing the substrate, CO₂ being the byproduct of interest.

The CO₂ seeps out the filter patch on the bag which simply prevents contamination while allowing gas exchange.

Eventually, the substrate becomes completely decomposed / colonized by the mycelium at which point CO₂ production is very low and it is ready to produce mushrooms!

Why would you recommend using self-activated bags over standard ones?

All other products on the market lack our self activation technology because we filed for, and have been issued with, patent rights on this technology.

Other products are already producing CO₂ before they even reach the store shelf. This is what I call a ""diminishing value shelf life"", where the longer it sits, the more useless it becomes, but the price remains the same.

In addition, these kind of products have no choice but to utilize slow growing Fungi due to the lack of a stable shelf life. Our customer activation technology gave us the freedom to use whatever culture of fungi we thought would work best.

As it turns out, Oyster Mushrooms have been shown in tests as early as 1974 to liberate 50% or more of the dry carbon within the substrate into CO₂ gas. They do this over a 30 to 60 day period, churning out gas at levels our competion is simply incapable of reproducing with their obsolete technology and slow growing fungi strains.

The time frame of gas liberation and the overall hardiness of the culture over its shelf life and how perfectly it fits a bloom cycle made Oyster Mushrooms the only clear choice.

Our MyCO2 Grow is the MyCO2 equivalent of our competition, only customer activated and with the ability to grow mushrooms!!

What advice would you give to customers using MyCO2 bags?

My advice is to not expect mechanical results from an organic product.

One of the biggest issues I face is customers expecting MyCO2 to perform like a compressed tank of CO₂ or a CO₂ burner on a monitoring system. This expectation is simply off board.

While the MyCO2 works, and works very well when used in smaller gardens, its effectiveness to cost ratio declines once you get into gardens larger than 15ft x 15ft x 9ft.

This is because the product has to fill the walking areas with gas in addition to the canopy areas. Also, the amount of gas is not consistent between bags and over the life of one bag. The product is a living breathing culture of fungi doing the best it can.

My advice to large scale gardeners is to use a mechanical CO₂ set up overall, and only use MyCO2 to supplement their set up. They will notice that they don’t need to refill their tank as often, and the burner doesn't turn on as often. One way or another, they’ll end up saving money.

What’s the best place to hang MyCO2 bags for optimum coverage?

The best way is to use A shaped metal light hangers and a rope ratchet to suspend the bag high above the lights and canopy so no shadows are cast.

Alternatively, MyCO2 bags can be hung or placed on a shelf just above wall mounted oscillating fans, which will move the CO₂ evenly across the canopy as it falls out the filter patch.

Is there any situation where customers shouldn’t add CO₂ to their environment? We normally advise customers that a lot of the CO₂ they add to their grow room will be extracted if they use an air exchange system.

You are 100% correct. I explain it like this: if you are controlling the grow room temperature by exchanging the air constantly, you are getting whatever CO₂ is available from nature (500 to 600ppm.)

If your extraction system can be turned off for 20 - 30 minutes without temperature becoming a problem, using a cycle timer or temperature switch to control your extraction fan, this’ll allow enough time for CO₂ enrichment between exchanges.

Naturally, all plants have different needs – do you have any plant specific guidelines?

The short answer is no, we do not offer plant specific guidelines. The reason is the long answer.

Well, when it comes to CO₂ there are four main groups, some of which don’t use carbon dioxide.

1. Green plants (the green colour comes from the green pigments in chlorophyll molecules)

These plants are completely autotrophic. To thrive, autotrophic plants need only solar energy, carbon dioxide, water, and a few minerals. All autotrophic plants use carbon dioxide for photosynthesis.

2. Semiparasitic plants

Semiparasitic plants, on the other hand, can't quite do it all from just water, CO₂, and sunlight (and a few other nutrients like nitrogen).

They also have to take some nutrients from an autotrophic host plant. They actually connect themselves to another plant and take some of the food they need from the host plant. Mistletoe is an example of this kind of plant (which is actually considered a fungi now).

Semiparasitic plants won’t need as much CO₂.

3. Insectivorous Plants

They use carbon dioxide for photosynthesis, but still needs a little something extra.

For example: Venus fly trap and pitcher plants catch and slowly digest insects and other unfortunate little animals that fall into their traps. Insectivorous plants can live without catching animals but they are a lot healthier if they can catch an occasional bug now and then.

4. Holoparasitic plants

Like semiparasitic plants, they have to be directly connected to an autotrophic host plant.

They have to get all their nutrients, energy, water, and carbon from the host plant they are attached to. But these plants have no green parts and can't perform any photosynthesis, so don't use carbon dioxide.

Since the vast majority of plants grown by our customers are those that absorb CO₂ during photosynthesis, we don’t offer any plant specific guidelines.