
Carbon Dioxide Generators for Cannabis Growers
There are a couple of reasons to use a carbon dioxide (CO2) generator in your grow room. First, CO2 allows plants to yield more buds; second, it makes them grow faster. By increasing carbon dioxide levels in the vegetative stage and in the first part of the flowering stage, you will maximize the crop yield if all other conditions are good.
Many growers use generators to supplement their gardens, but if you are a first-time cannabis cultivator, you may not know much about the practice. In this comprehensive guide, you will learn the basics of CO2 supplementation and how a generator can help.
How Marijuana Plants Use Carbon Dioxide to Grow
Humans and plants have a symbiotic relationship. People exhale carbon dioxide and inhale oxygen, while plants inhale carbon dioxide and exhale oxygen. Plants take in CO2 through their stomata (leaf pores), which initiates photosynthesis.
The combination of carbon dioxide, water, and light allows plants to make energy. During photosynthesis, a plant combines the carbon dioxide it pulls from the air with the water absorbed through the roots. As light is added, a chemical reaction occurs between the carbon dioxide and the water. This reaction produces oxygen as well as C6H1206, a glucose-like substance that the weed plant uses for energy.
Outdoor gardens typically receive ample CO2, and when conditions are good, they create extra food that is stored away for later. Where cannabis is concerned, the surplus food produces a higher yield much sooner.
Factors to Consider Before Using a CO2 Generator
The benefits of CO2 supplementation may make it seem like a must-do. However, you will have to make a few considerations before setting up your generator. Because the practice requires a substantial investment of money and time, it is important to be sure your garden is ready by addressing other yield-inhibiting factors.
If your plants’ root systems are weak, they will die even if CO2 is added. A healthy root system requires sufficient aeration so it can use oxygen and absorb nutrients and water. Therefore, it is important to ensure that the growth medium is not over- or under-watered.
Pests and pesticides must be carefully monitored so that carbon dioxide can do its job. Unless these issues are handled, cannabis plants will either fail to thrive or they will die. Chemicals are often harmful to the environment and the consumer. Fortunately, there are numerous chemical-free, all-natural pest control methods which are easy to find in every state, from Maryland to Washington. A plant suffering from a nutrient deficiency or surplus will not benefit from added CO2. When using a chemical fertilizer, it is possible to add too much. Natural fertilization methods are effective, but they require additional maintenance. It is crucial to monitor your plants for deficiencies, as they make it nearly impossible for the crop to remain healthy.
Unless there is enough light, any added CO2 simply goes to waste. As previously explained, photosynthesis only occurs with the combination of CO2, light, and water. Strong lighting sources such as LEDs or HPS systems work well, especially when providing 7500 – 10,000 lumens per square foot.
Increased CO2 levels also bring more humidity. To shield your plants from mold, mildew, and bud rot, it’s best to invest in a good dehumidifier.


Ways to Supplement Your Crop with CO2
First and most importantly, you should set up the generator so that CO2 rains down from above. Carbon dioxide is quite heavy, so it will naturally move to the bottom part of the room. Consider installing upward-facing fans so the CO2 never reaches the floor.
Though some feminized weed seed growers see success with compressed CO2, generator usage is the preferred method. However, generators make a great deal of heat, so they are best for large grow rooms. On the other hand, compressed carbon dioxide does not create much heat, so it is good for small spaces.
When using a CO2 generator, it is best to turn it off when the grow lights are off, as photosynthesis does not happen without light. Another important thing to consider is the usage of timers and climate control systems. These additions will make it easier to manage temperature, humidity, and carbon dioxide levels. Though such systems are often costly, the assurance and convenience they provide make them a worthwhile investment.
Other Ways to Supplement Your Cannabis Garden with Carbon Dioxide
If you’re just starting out and can’t yet afford a CO2 generator, there are other, less expensive ways to boost levels in your grow room. Simply breathing on the plants is one option; however, it is unlikely to provide enough CO2 to yield the desired result.
Some pot seed growers use methods requiring open flames, such as Bunsen burners. This type of CO2 generator is difficult to oversee, and you will not know just how much of the gas is released. Furthermore, the open-flame method is very dangerous, as grow rooms are typically full of heat, water, and electrical wiring. The risks of explosion and fire outweigh the benefits provided by these methods of CO2 generation.
The Pros and Cons of CO2 Supplementation
Now that you have learned more about using a CO2 generator, it is time to learn about the advantages and disadvantages of the practice.
Advantages of CO2 generator use:
- You will get a bigger yield, faster. If you have already addressed other yield-limiting factors (such as lighting,) carbon dioxide supplementation may make your plants grow about 20% faster, providing a bigger and quicker yield.
- You will be able to work at a higher temperature. A level of 1200 – 1500ppm (parts per million) of CO2 in the grow room will allow you to work at temperatures up to 35°C or 95°F. If you are using hot and bright lights, carbon dioxide makes it easier to keep the temperature within a favorable range.
- Your operation will be more secure. CO2 supplementation is beneficial in sealed grow rooms because you will not be venting aromatic air. Certain supplementation methods, such as generator use, create natural fragrances that conceal the well-known odor of cannabis.
Disadvantages of CO2 generator use:
- It will not work well without bright lights. For supplementation to work, you’ll likely need strong LEDs or HPS lights to create enough brightness for your plants to use the additional CO2.
- You will have to seal the grow room. Although light supplementation does not require a complete seal, if you are trying to keep the grow room’s CO2 level between 1200 – 1500ppm, you will need to make the room airtight.
CO2 can get expensive. It may be costly to begin the process, especially if you are growing a large indoor garden. The easiest and least expensive ways to add carbon dioxide are not very effective at providing high levels over time, but they are a good way to try the practice out. The best setups are a little costlier, but in the long term, they end up paying for themselves in the form of higher yields.
Does It Make Sense to Supplement Outdoor Gardens with CO2?
The atmosphere naturally provides cannabis plants the perfect dose of carbon dioxide. Furthermore, it would be hard to control the dispersal of the gas into an outdoor garden, and the disadvantages would very likely outweigh the benefits. The surest way to control carbon dioxide levels is to keep the growing area sealed, so using it in a greenhouse or tent may be enough to maximize outdoor (or semi-outdoor) yields to the extent possible.
How Much is Enough?
Generally, the air we breathe has a CO2 concentration of about 400ppm. However, during the evolution of plants, atmospheric carbon dioxide levels were much higher. As you may imagine, plants can absorb much more CO2 than is found in the atmosphere.
A cannabis plant may use upwards of 1500ppm during photosynthesis. For supplemental CO2 to have a beneficial effect, use your generator to maintain that level. Anything extra will simply go to waste because your plants will not be able to use it to make energy.
If other conditions in your indoor cannabis garden are optimized, CO2 will be much more effective. When plants are robust and healthy, they are photosynthesizing as efficiently as possible. However, when they are weak, additional CO2 may not have much of an effect. Take care of your chronic plants, and the rest will fall into place.
Preparing Your Grow Room for a CO2 Generator
There are several ways to get your grow room ready, and there are numerous factors to consider. Additional CO2 works better in hotter environments, so you will need to keep that in mind. Here, you will learn how to modify your grow room to prepare it for carbon dioxide generator use.
- Increase the temperature: If you are gradually working toward the upper CO2 limit of 1200 – 1500ppm, you will need to raise the temperature in the grow room. Though most spaces should have a temperature of 20 – 27°C (or 68 – 82°F), the usage of a CO2 generator requires a temperature of 29 – 35°C (or 85 – 95°F). That is a significant increase, so be sure to observe your plants for signs of heat stress.
- Seal the space: If you do not already have a sealed grow room, this modification is optional. When there is a great deal of CO2 in the air and the room is not well sealed, you may waste energy and money keeping levels high. If you do seal the room, you will need to consider humidity and heat control methods as well.
- Minimize humidity: For most cannabis cultivators, humidity is a top priority. If you seal the grow room, you will have to continuously monitor the humidity level. Try to keep it at or below 60 – 70% to reduce the chances of mold or mildew growth. If necessary, purchase a commercial-grade dehumidifier.
- Have plenty of light: As previously mentioned, if there’s not enough light, your CO2 generator will not have much of an effect. Make sure there is enough light in your grow room, at least 7500 – 10,000 lumens for every square foot. Each bulb’s light output is listed on its packaging, and you will need to do some basic math to ensure there is sufficient lighting for the area. Strong lighting is a must when using a CO2 generator during cannabis cultivation, and powerful lights will also work to keep temperatures high.
Using a CO2 Generator in the Vegetative and Flowering Stages
Here, we will discuss how CO2 affects cannabis plant growth during different stages, and you will learn how to maximize growth and yield.
- During the vegetative stage, CO2 greatly increases plant growth. Therefore, generator usage is an easy way to grow bigger plants much faster. Just keep the generator running during daytime hours, and that is it.
- In the flowering stage, it is possible to see accelerated growth and greater bud production with CO2 usage during the first two to three weeks. So far, the effects of CO2 supplementation after flowering have not been proven. However, many growers believe it does work, and they suggest leaving the generator on until two weeks prior to harvest.
Using CO2 during the vegetative and flowering stages will help you ensure that you are giving your plants everything they need for maximum production and quality. Experienced cultivators often decide that a carbon dioxide generator is a worthwhile investment of time and money. Once you have grasped the basics of cannabis cultivation, adding carbon dioxide may be just what you need to master the craft. Your crop will greatly appreciate the energy boost, and you will love the high yield.
In Closing
In the very near future, the country’s prohibitions on recreational and medicinal cannabis use will likely end. As a cannabis cultivator, you’ll have control over the crop from seed to harvest which is music to the ears of growers in Wisconsin and Kansas, where growing is not yet legal. You can choose your strain, your location, the type of equipment you will use, and the level of effort you are willing to put into the operation.
It is great to have the freedom to grow a cannabis crop like those in Alaska, but that freedom comes with responsibility. As a grower, starting with high-quality American seeds from an online provider like kindseed.com is just the beginning. learning about your plants will help you increase yield and medicinal properties. Carbon dioxide is of special interest to cannabis growers, and it is a crucial part of the process of photosynthesis. People and plants enjoy a symbiotic relationship, and with the proper use of a carbon dioxide generation system, you can make that relationship even more fruitful.