Supplementing your plants with extra CO2 can increase your yields and growth by up to 20%, but what's the best way for a cannabis grower to use CO2? There's the right way and the wrong way to use CO2, and unfortunately a lot of people use CO2 in the wrong way and not getting any of the benefits!
Cannabis Plants "Breathe" CO2 instead of Oxygen CO2 is short for "Carbon Dioxide," an odorless gas that’s in the air you’re breathing right now.
Cannabis plants need CO2 as part of the process of making energy from light via photosynthesis. Without CO2 your plants will "suffocate" and die. That's part of why it's so important for your plants to get plenty of fresh air.
For growers using lower powered grow lights (like CFLs or fluorescents), there's often more than enough CO2 in regular fresh air for your plants to be able to process all the light they're being given. If your plant doesn't need more CO2, it won't help very much to add more because they've already got more CO2 than they can use.
If you're using CFLs or fluorescent grow lights like T5s, there's probably already plenty of CO2 in the air for your plants to process all the light they're being given
But things are different when there's more light being provided than your cannabis plant can naturally use. In high-light situations, supplying more CO2 can allow your plants use more of that light, which results in increased photosynthesis. By getting your plants to produce more energy from the same amount of light, they'll reward you with faster growth and bigger yields!
As an added bonus, supplementing with CO2 in this way makes your plants more resistant to heat and light stress!
One of the downsides is that supplementing with CO2 can be expensive. So before you start adding CO2, it's a good idea to figure out how much, if any, you should be providing to get faster growth.
CO2 Supplementation Works Best With MH/HPS and LED Grow Lights!
Instead of lungs, plants use hundreds of tiny pores in the leaves (known as stomata) to get CO2 out of the air. As a byproduct of photosynthesis, plants release oxygen back into the air. The photosynthesis process generates most of the oxygen in our atmosphere. Without plants using CO2 for photosynthesis, we would have no oxygen to breathe!
Benefits of Adding Extra CO2
Bigger Yields, Faster Growth - If you’ve maxed out the other limiting factors (especially light), CO2 can make your plants grow up to 20% faster, produce bigger plants, and enhance your yields.
Higher Temperature is Okay - Maintaining 1200-1500 PPM of CO2 in the grow area allows growers to keep temperatures much higher than normal, up to 95°F (30°C). For growers with hot bright lights, this can make it easier to keep temps at a range their plants will like.
Security - CO2 enrichment can be beneficial for security if you seal your grow room since you’re not venting out smelly air. Certain methods of adding CO2 like using a CO2 generator will also create natural smells that help cover up the smell of cannabis directly.
Disadvantages of Adding Extra CO2
Not As Effective If You Don't Have Bright Grow Lights - As far as light intensity is concerned, you probably need either MH/HPS or strong LED grow lights to produce bright enough light for your plant to be able to use the extra CO2. CFLs and T5s probably aren't bright enough to get great results with CO2.
May Need to Seal the Grow Area - Although adding just a little CO2 doesn't require a sealed room, when trying to maintain very high levels of CO2 (like 1200-1500 PPM) you probably need to seal up grow area so it’s airtight in order to prevent CO2 from leaking out.
Cost of Adding Extra CO2 - It can be expensive to get started if you want to inject a whole lot of CO2 into your grow area, for example in big grow operations. The cheapest ways to add CO2 are actually not very good at providing a lot of CO2 over time, but can be a great way to "dip your feet" and try CO2 out. The best CO2 setups in the long run are a bit more pricey to get started with, though they become a lot cheaper once you've got your initial supplies.
How Much CO2 Do I Need?
Even though CO2 levels in the air are much lower today at around 400 PPM, plants are still able to use CO2 levels at the higher concentrations, allowing them to produce more energy from the same amount of light. Growers can take advantage of this increased growth by providing extra CO2.
That means in order for CO2 enrichment to be the most effective, you want to maintain levels up to 1500 PPM of CO2 in your grow space with very bright light.
Plants Can Use Up to 1200-1500 PPM of CO2
CO2 supplementation works best when everything else in the grow space has already been optimized, and for most growers, a little optimization may result in even bigger returns on yields than adding CO2!
If you're using smaller grow lights with lower light levels, you will need less CO2!
Plants should have fast & healthy growth - No nutrient problems and no pest problems if possible. It will also maximize your yields by using plant training. Healthy and vibrant plants respond really well to extra CO2!
You should maintain high temperatures, between 85°F (30°C) and 95°F (35°C).
When you’re adding CO2, especially higher amounts, you will get the best results at higher temperatures.
happy growing