Should I Use CO2 in My Grow Room?
I recently found out about using CO2 (or carbon dioxide) in my grow room. I was a bit thrown off by this because at first, I didn’t understand why you would add CO2 to a grow space. Once I did some research, I quickly remembered some high school lessons on plant photosynthesis and realized why you would want to use CO2. It makes complete sense to use CO2 for weed plants.
You should use CO2 in a grow room to increase yield. Using CO2 in a grow room will speed up the time it takes to grow marijuana plants by up to 30% faster than normal. Using CO2 in the daytime when lights are on during photosynthesis will increase the size of your plants faster than not using CO2.
In this article, I will go over why you should consider using CO2 to maximize the time it takes to grow your weed plants and to maximize the size of your weed plants. I will also go over some other important things to consider when using CO2.
So, if you’re ready to learn more, then please read on…
Why You Should Use CO2 in Your Grow Room
Marijuana plants absorb CO2 during photosynthesis just like all other plants. This happens during the daytime so only add CO2 during this time. Therefore, providing CO2 is equal to feeding your weed plants just like when you add fertilizer to the water.
Absorbing CO2 is a natural process for plants, which means you should use CO2 especially, if your grow room or tent is not in the lowest level of your home. The reason being is that CO2 is heavier than air (oxygen) so it will fall and pool in the lowest levels of your home. This is great if you’re trying to grow weed plants there.
It’s important to note that adding CO2 will not increase THC. When I was doing my research, I read that some growers were hopeful for this to happen. What it will increase though, is the size of the buds.
If you want to grow weed plants in the quickest time possible then adding CO2 is a must for you. The word on the street is that CO2 speeds up the grow time of your weed plants as much as 30%. That’s a huge time saving! It also means you can grow more plants throughout the year when you can save 30% on each grow.
To capture quickly what I just told you. Using CO2 will:
- Feed the weed plants what they want, which is CO2.
- Speed up the time it takes to grow the weed plants from seed to harvest.
- Adding CO2 will encourage larger buds which is what we want when growing weed.
How Much CO2 Do You Need in a Grow Room?
Everyone will require different amounts of CO2 added to their grow rooms based on their own CO2 levels. If your grow room is in a basement, you will have higher levels of CO2 than if you grow in an attic or 2nd floor of a home.
With CO2 it is important to know what the levels are if you are adding more to the environment. The main reasons being at high levels CO2 can be toxic to your plants and at even higher levels it can be harmful to you. Therefore, it’s extremely important to get yourself an indoor air quality tester that can detect CO2. These meters will test CO2 by PPM which is all you need then you can adjust accordingly.
Check out this indoor air quality meter over on Amazon.
Let’s talk about CO2 levels now and what you should be shooting for in your grow room. CO2 is measured by parts per million (PPM). A normal outdoor reading of CO2 would be 300 to 400 PPM and indoors is approximately 500 to 800 PPM.
The CO2 range for your grow tent or room should be somewhere around 800 to 1100 PPM. The lower range will be fine for the vegetative phase and the higher end for the flower phase.
Some growers will recommend using higher levels of CO2 (as high as 1500 PPM), however, for the added CO2 your plants probably won’t grow much if anymore than if you kept the levels between 800 and 1100 PPM. You must consider the cost of adding the CO2 as well.
There gets to be a point where the level is more harmful than good. 1800 ppm and higher is too much for your plants and will eventually kill them. When the levels get higher than 4000 PPM, a human will start feeling the effects. Dizziness, pukey, etc. At over 4000 PPM the CO2 levels are now dangerous for you.
So, to sum up. Keep the CO2 levels in your grow tent or room between 800 PPM and 1100 PPM. For maximum results.
When Should You Introduce CO2 in Your Grow Room?
I found some interesting answers to this question when researching. Having a lot of growing experience really helped me to easily understand the mechanics of this situation and since you’re still reading, I will give you my take on this.
Some growers state you should only use CO2 during the flowering phase. I understand this thinking because it’s the end result of a much larger yield that everyone strives for, correct?
I feel that the only time you would add CO2 during the flowering stage only would be because you can’t afford to run CO2 for the whole grow.
Using CO2 during the vegetative phase will speed up the weed plant’s growth. This means the plants will be ready for the flowering phase much quicker. This also means you will probably have a much stronger plant in general. The stalk will be thicker allowing larger buds to grow.
To sum this section up. Adding CO2 during flowering/budding is crucial and if you can afford it add CO2 for the whole grow.
I should add that when running CO2 make sure the grow tent or room is 24 Celsius (75 Fahrenheit) and higher to maximize the absorption rates. At colder temperatures, the plants will not absorb as much CO2.
So, you will be wasting your money if the area is not warm enough. If you want some excellent ideas on how to heat a grow tent or room check out this article.
Best Ways to Add CO2 to a Grow Tent or Grow Room.
Ultimately, the best and easiest way to add CO2 to your grow area is to ventilate. Since CO2 can be found at higher levels near the floor make sure to draw fresh air into your grow space for lower and expel it from higher up in the grow room.
Of course, you can purchase CO2 and if you have a bit of scientific interest you can create some yourself. Lets, look at your options.
- For large grow rooms and tents, you could look at purchasing a CO2 generator. When I say large, I am thinking of areas over 10’ x 10’. This is more for a commercial type grow. For growers like myself that can legally only grow 4 plants at a time, this would be a waste of money.
- Also, for larger grow rooms a compressed CO2 tank with an emitter is an option. Again, you will need to consider the cost when buying one of these. Is it worth it for what you need?
- For most smaller growers like myself, you probably want to consider something such as the Exhale CO2 bags. They last quite a while and are super easy to use. You can purchase them in different sizes as well. Check them out here on Amazon.
- Another easy option is the Green Pad CO2 pads also available on Amazon. You hang them up in the grow room or tent and they are activated by the humidity. You spray them with water, and they start generating CO2 right away. The room does need to have at least 35% humidity.
- If you have an interest in science (kidding), you might be interested in researching how to create CO2 by adding different compounds together. Such as mixing yeast and sugar or mixing baking soda and vinegar. When combined, these compounds produce some CO2.
It’s worth noting that regardless of how you add CO2, make sure the ventilation system is not running at the same time. You don’t want to be venting it right out of the grow room. You can resume ventilation at night.
When to Stop CO2 During Flowering?
There comes a point when there is no benefit to adding CO2 to your grow room and that would be just before it’s time to harvest your weed plants.
I would recommend stopping the use of CO2 in your grow space approximately 2 weeks before you cut it down. You will also be stopping fertilizing about a week before harvest so this all ties together.
There is no added benefit at this point. You want your weed as clean as possible from things such as CO2 or fertilize before you reap your growing efforts. This will ensure a much tastier bud when done.
Conclusion
I really enjoyed learning about using CO2 in a grow room. There is indeed a benefit to doing so and I would recommend anyone to try it if it is in your budget to do so. Just remember you need to have an air quality tester running in the room to make sure your levels are safe for the plants and for you.
Good luck!
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