In order to burn enough fuel to reach the proper CO2 levels, you sometimes run into adverse side effects, such as producing an unhealthy amount of dangerous carbon monoxide. It's important to only use safe ways of generating CO2. It’s dangerous to store your bottled fuels indoors (some people are able to use their municipal natural gas, and don’t need to store fuel, which makes this point moot for them).
Note: The cheaper methods of CO2 generation (like burning denatured alcohol in a small stove) make CO2 hard to regulate and can be very unsafe…. Because these methods use an open flame and combustion to produce CO2 in a sealed area, there are many safety and fire concerns with this method. It's highly recommended that you buy a CO2 generator that has safety features to help prevent fires. Compressed CO2 can be one of the most controlled ways of injecting CO2 to your grow space. Ability to have fine control over PPM in room using a regulator or controller. Can be automated with a controller, so relatively automatic once everything is set up. The equipment you need to get started is expensive, this is one of the most expensive ways to get started with enriching CO2. You must lug tanks of CO2 to and from your grow area, which is a possible security concern depending on your grow area and where you get your CO2. You can enrich the air with CO2 beyond what’s safe for plants or people, so you must use great care to keep the PPM in the right range, and to avoid breathing air in your sealed grow area.
In some places, you may need a permit or license to get tanked or bottled CO2. Note: It’s usually cheaper to get tanked CO2 from a welding supply store as opposed to a hydroponics store. Fermentation uses natural processes to produce CO2. Can cause an unpleasant odor during the fermentation process. CO2 bags use mycelial mass (fungi) growing on organic matter to produce CO2. Even in a very small space, growers may need to hang 4-5 or more bags (or more!) over their plants in order to achieve the right PPM in their grow area. Some growers have trouble getting the fungus to grow properly (although you’re not supposed to need to do anything for these bags to work) 5.) Compost. Some growers use the composting process, which produces a small amount of CO2. With home-made compost, it's very difficult to know if you're even adding a significant amount of CO2. The pre-made systems like CO2 Boost are better, but they're still expensive and don't produce a whole lot of CO2. While this method can be effective in the short term, it can be incredibly expensive and time-consuming to keep this method going for long. Very small cost to get started, since dry ice is relatively cheap and easy to obtain. The biggest safety hazard is burning your skin from touching the dry ice without protection. Does not raise temperature of grow room, in fact dry ice will slightly cool grow room. Not recommended for long-term use because it can be a huge pain and expense in the long run since dry ice doesn’t last long. Must manually keep adding dry ice at least once/day. Can be very tough to regulate the CO2 levels in the air. Dry ice must be used immediately, so you’ll be constantly going back for more. Humans breathe out CO2 with every breath, and since that CO2 is free, it can be tempting to think you can add extra CO2 to your grow room, all natural, with no equipment needed. Unfortunately this likely won't add enough extra CO2 to be make a difference. It's good to spend time with your plants, in fact I love hanging out in the grow room, but breathing on your plants probably isn't going to make them grow any faster. FAQs, Tips & Background Info to Get the Best Results from CO2 Injection. When people are talking about how much CO2 is in the air, they generally measure in “PPM” or “parts per million.” In regular air, the amount of CO2 is approximately 300-400 PPM (about 0.03-0.04% of our air is CO2). But to get benefits from adding CO2 to your grow room, you need to add enough extra CO2 to maintain 1200-1500 PPM (0.12-0.15%) of CO2 in the air. When CO2 concentrations get even higher, to 10,000 PPM (1% of air), it becomes poisonous to animals.
In some cases greenhouse growers will use this to their advantage by raising the CO2 concentration to 10,000 ppm or more to kill bugs like spider mites (but of course they're careful to keep humans and animals far away!). But since you'll be using much lower concentrations of CO2, it is very unlikely you'll ever expose yourself to negative effects. It's still always a good idea to protect yourself by staying out of the grow space as much as you can and otherwise reducing how much you breathe CO2-enriched air. How can plants use more CO2 than what’s found naturally in the air? A long time ago, there was a lot more CO2 in the air than there is now. Some scientists believe that this is why many plants can take advantage of more CO2 than what’s naturally found in the air. Why is CO2 enrichment only effective during the “day” period? Like nearly all plants, marijuana stops using CO2 during the night (dark period). CO2 is primarily used in the day by the plant as part of photosynthesis (turning light into energy), so if there's no light, there's little need for CO2. Therefore, flooding your grow area with CO2 during your dark period can be a waste of time and money.
CO2 mainly provides benefits when the lights are on. Why do you need powerful grow lights for CO2 enrichment to be most effective? It’s common for growers try to add CO2 to their grow area, without realizing that something else is limiting the growth of their plants.