Indoor cannabis cultivators will do everything in their power to enhance photosynthesis. From high-powered lighting apparatuses to complete high-end nutrients, growers spend vast sums of money to ensure their plants are getting everything they need. One of the most important factors in the chemical equation that makes up the photosynthetic process is carbon dioxide. Because of this fact, many indoor horticulturists take advantage by supplementing additional CO2 to the CO2 that is already present in the atmosphere. The first thing any grower who wishes to use CO2 must do is to decide which CO2 method to use.
Mycelium-based CO2 Devices
Mycelium-based CO2 devices are the CO2 buckets or bags sold at hydroponic stores. These CO2 devices use a medium to cultivate mycelium (fungus) which produces CO2 as a byproduct as it grows. The bag or bucket is placed in the grow area and the CO2 produced by the mycelium mixes with the atmosphere and raises the CO2 level. These devices work great for small areas like closets or grow tents. They do not produce any heat and do not require automation equipment to operate. The disadvantages are that there is no control over the amount of CO2 in the room and they are not really practical for large grow operations.
Compressed CO2 in Tanks
One way growers can boost the CO2 in the grow room is by using compressed CO2 in large tanks or canisters. These tanks require a regulator to release the CO2 into the atmosphere. A timer, the CO2 tank, and the regulator are all that are required to start supplementing CO2 but the entire system will work more efficiently with the addition of a CO2 controller. A CO2 controller will monitor and regulate the actual CO2 levels in the garden. These levels are determined and set by the user. The fact that they do not create any heat and have the ability to be fully automated is why so many growers opt for CO2 enrichment with the compressed tank method. The disadvantages of this method are the handling and transport (the tanks are heavy and bulky).
The most popular choice for CO2 enrichment in large areas is CO2 burners. These devices burn either natural gas or liquid propane and emit CO2 in the process. CO2 burners come in various sizes, including very large units designed for large greenhouses or commercial buildings. Like compressed tanks, CO2 burners are most efficient when automated by a CO2 controller. The controller determines when additional CO2 in the grow area is needed and ensures a consistent level of CO2. The advantages of CO2 burners are they are suited for large areas and they are relatively cost efficient. The disadvantage of CO2 burners is the heat they emit can build up in the grow area if not properly addressed.
The CO2 Concentration
Once the gardener decides what device to use for CO2 enrichment, they need to decide on the concentration of CO2 they wish the grow room to have. Considering the ambient CO2 concentration in our air is just under 400 PPM (a bit higher in more populated areas) any CO2 enhancement beyond that level will give the garden some benefit. For beginners I normally recommend starting at 700-900 PPM. This is because the higher the CO2 concentration in the room, the higher the operating temperature must be to effectively use the CO2. At 700-900 PPM of CO2, a grower can operate the room at 75-80 degrees F and still get the full benefits from the CO2 they added to the atmosphere. More experienced growers, or growers confident in their control over the room’s environment, the CO2 levels can be pushed to 1500-1700 PPM. In order to gain the full benefit from this high concentration of CO2, the room’s operating temperature needs to be around 82-87 degrees F. Along with increasing temperatures, growers will need to adjust the nutrient concentration accordingly. Plants stimulated by increased CO2 will require a higher concentration of nutrients.
Along with high-powered lighting and quality nutrition, CO2 enrichment is an essential component to maximizing production in an indoor garden. By utilizing one of the devices to enrich the environment’s CO2 concentration, cannabis cultivators can manipulate the photosynthetic process and reap the rewards in prolific harvests.
Eric Hopper is the Editor in Chief for NUGL Media. He can be contacted at [email protected].