do I add CO2 to my garden? What
do I have to worry about?
first thing to decide is which
method you want to use to enrich
your room. The goal is to fill
a room with the desired level
of CO2 as quickly as possible.
Injection System runs off of carbon dioxide gas (much like a soda dispenser) and is a good choice for a small room. The drawbacks to this kind of enrichment system is the need to consistently change CO2 tanks, and the fact that it can often take a long time to enrich a room. It's a great choice for smaller systems. The largest room this system should be used with is 10x10 (and that’s pushing it a little). We've designed a CO2 Calculator
to help you figure out how long to run your emitter system.
We prefer to use a CO2
Generator for larger rooms. Generators come in different sizes and you can purchase a generator that is optimum for your room size. (You want a generator that is capable of enriching your room in 5 – 10 minutes.) We have a
to help you choose the correct size generator.
CO2 generators use one of two types of fuel. You can choose to run it off of liquid propane tanks or a natural gas line. Liquid propane is fine, but the tanks need to be regularly refilled (which can be a real pain). Natural gas runs off of a natural gas line, which once installed properly, is safe, low maintenance and easy to use.
CO2 emitters do not add any extra heat to a grow room, although CO2 generators do. Depending on the size of generator you choose, you may be adding a considerable amount of heat to your grow room. This combined with grow lights can create a very warm room indeed. The good news is that heat is a necessary catalyst for plants to use the added CO2 and that they prefer much warmer temperatures than they do without CO2 enrichment. Most plants prefer temps of up 90 – 95 degrees with CO2 enrichment. If your room doesn’t heat up this warm you may need to bring in a heater (this can be the case for greenhouses). Usually, however, the room will get too hot and an air conditioner will be employed.
Humidity is the second major issue with CO2 enrichment. CO2 enriched rooms can get extremely wet. This increase in RH is due to the fact that the plants’ metabolic processes are occurring at a more extreme rate and water is flowing up through the roots and out of the leaves quickly. Most plants do not thrive in an overly humid environment. Most plants prefer an environment between 55 and 65 RH. The preferred level of humidity fluctuates as the plants move through their seasons. They will like more humidity in the vegetative stage and less in the fruiting/flowering stage. As the plants grow older, more leaves are produced and more moisture is created. This will become a problem for most growers (although this will vary depending on the environment in which you live; if its dry and warm outside, you probably will have few humidity issues).
When the level of humidity gets too high it needs to be removed with either a vent
fan or a dehumidifier. The most common problem for most growers is finding the fine balance between exhausting moist air, enriching a room and keeping the temperature at the right level. If this is done incorrectly, CO2 will be exhausted with the air and plants will not get the benefit of the CO2 enrichment. There are many solutions to this conundrum and we will tell you two of our personal favorites. Feel free to modify these examples to fit your needs.
1. If you are using a CO2 emitter system, we suggest use of the Fuzzy Lgoic CO2 Controller from C.A.P.. It is very affordable, easy to use and extremely efficient. It will turn CO2 enrichment on and off at predetermined intervals, based on basic information you provide. (Room dimensions, desired ppm, output level of emitter) It does all the calculations for you and creates a CO2 on/off schedule coupled together with vent
fan control for airing out the room. It will turn the CO2 OFF before it turns the vent
fan ON and vice-versa. It comes standard with a photosensor which ensures CO2 will be turned off in the dark period when plants are unable to use it anyway.
2. For larger situations when a CO2 generator is employed, heat and humidity are even more of an issue. In this type of growing situation, we highly recommend the grower invest in the CDMC
Package from Green Air, as well as a temperature/humidity
controller. For a detailed explanation of how this works, click on the two product links above or click here to see how they work together.