Carbon dioxide (CO2) is a gas that fills our atmosphere. People inhale oxygen and exhale carbon dioxide. Plants absorb carbon dioxide and release oxygen. This is called the oxygen and carbon dioxide cycle.
The importance of CO2
Carbon dioxide is critical when it comes to promoting and enhancing plant yields. CO2 is one of the main conditions for photosynthesis for plants. Plants absorb carbon dioxide, water, and solar energy for photosynthesis, thereby producing organic matter and oxygen. Oxygen is released back into the atmosphere, organic matter is absorbed by plants to grow.
Carbon dioxide levels in the atmosphere are around 400 ppm, but the rate is rising every year due to increased anthropogenic emissions. Studies show that giving your plants extra CO2 can increase yields by up to 20%. That is as long as you supply enough light to them.
When you grow indoors, keeping an eye on the CO2 levels indoors can help you grow marijuana better. The amount of CO2 in the air has a profound effect on the rate of photosynthesis and plant growth. Photosynthesis speeds up as the amount of CO2 in the air increases, as long as there is enough light to power it (to an upper limit). If a cannabis plant does not get enough CO2 it will continue to grow until its stored sugars are depleted. Once that happens, their metabolism decreases, and they show little to no signs of growth. On the other hand, if a plant gets too much CO2 it will slow down or even stop photosynthesis. The trick is finding the right gas level for a grow space to speed up photosynthesis and lead to abundant growth and boosted yields.
When we need to add CO2 for our marijuana plants?
We recommend trying to use CO2 in your grow room after you have had a few successful plantings. Once you are ready to use CO2, you must manage the gas at the right time. Because photosynthesis only takes place during the day when there is light. In the dark, the addition of carbon dioxide should be stopped. And plant respiration releases carbon dioxide at night, the level of carbon dioxide can become uncontrollable.
Cannabis has two important periods, the vegetative period and the flowering period. The vegetative period is the growing period of cannabis that focuses on getting bigger and stronger. This is when carbon dioxide can help plants grow from seedlings to larger plants with many future bud sites and large fan leaves. Extra CO2 during flowering can increase the number of buds. At the same time, we must also follow the principle of adding when the light is turned on and stopping when it is dark.
How to add extra CO2?
There are three CO2 enrichment methods for indoor growers.
- Compressed CO2，as the name suggests, CO2 is collected, compressed, and stored in tanks.
- Dry ice is the solid form of carbon dioxide. As dry ice melts, it turns into carbon dioxide gas.
- CO2 Generator is burning some type of fuel to release CO2, such as natural gas propane or something like this. When burning the gas to produce carbon dioxide, it also releases a lot of heat.
In addition to the above three ways, there are other ways to add carbon dioxide, you can choose a suitable way to inject more carbon dioxide into your cannabis plant according to your needs. Personally suggest that beginners choose to use compressed CO2, because it is a controllable and safer way. Other methods can even be dangerous if you don't really understand how they work. So compressed CO2 is a better option.
How much CO2 do you need?
In a well-ventilated indoor space, the concentration of CO2 should be around 400 ppm, which leads to growth rates like what you would expect if you were growing your plants outdoors. If CO2 is above 3,000 ppm it starts to become dangerous for humans to breathe, and at 5,000 ppm can be lethal to humans.
Most growers believe that carbon dioxide levels of 1200ppm-2000ppm will have a significant effect on improving the yield of cannabis plants; some growers believe that levels of 800ppm-1000ppm are better. However, this does not have an exact value. Cannabis cultivation is constantly changing, and many factors are interacting and restricting each other, which requires adding carbon dioxide as the growth stage changes based on your experience.
In conclusion, if you are new or you only grow one or two cannabis plants, it is not recommended that you consider adding CO2. Although CO2 can improve cannabis yields, it should be considered an upgrade as a last resort. Adding extra CO2 requires sophisticated environmental control equipment to control and ensure the CO2 level you need. And note that you should make sure you provide enough light to your cannabis plants when adding extra carbon dioxide.