HOW TO USE CO2 IN PLANT GROWTH

Carbon dioxide or CO2 is the essential gas for supporting plant life. It is a colorless, odorless gas, found in small quantities in the air.

In order to make the most of indoor gardening, it is necessary to provide plants with all the constituents of the above mentioned process: light, CO2, water and nutrients. If plants receive enough water, but have weak supply of nutrients or light, it won’t work out. Injecting CO2 can offer great benefits, when performed by a skilled and experienced gardener. However, the beginner may easily kill his plants by injecting CO2 in inappropriate manner.

During the process of photosynthesis, plants absorb carbon dioxide from air and break it down into smaller compounds: oxygen and carbon. Some amount of oxygen is used by a plant for its own needs, but the major amount of it is sent back into the air. Carbon is used by plants as the building material: first, under the influence of light, carbon mixes with water and forms a sugar molecule; then this sugar molecule is turned into carbohydrates, which in combination with nutrients are used to build new plant tissues.   

Several important pre-conditions should be created before using the increased CO2 levels. First of all, it is necessary to provide a very bright lighting for the plants (more than 20 watts per square foot). Otherwise, there will be little or no increase in plant growing. It is also necessary to increase temperature slightly (about 3-5 degrees). Finally, do not forget to supply plants with adequate amounts of water and nutrients, since increased photosynthesis will require more resources.

In the natural environment, plants usually use about 300-600 ppm (parts per million) of carbon dioxide, which is available in the atmosphere. However, plants can handle significantly larger amounts of CO2. With 1500 ppm of CO2 consumed, plants can grow twice as fast as they grow under the normal conditions. However, in most cases about 40% - 50% of growth increase is achieved.

Ideally, CO2 should be maintained at steady level constantly. To reach this goal regular injections of small amounts of gas are needed. However, it is not always possible to perform such operations, since there is a requirement to ventilate the growing site thoroughly right before the injection.

The biggest catch about carbon dioxide injection is not to exceed limits. Most of the plants will be destroyed, when the CO2 levels reaches 2000 ppm. Besides, such elevated levels of CO2 are also toxic for humans. That is why it is recommended to vent the room before injecting CO2 in order to remove excess CO2 and prevent its accumulation.

Usually, in order to increase CO2 levels special CO2 control devices (either bottled CO2 or CO2 generators) are used in hydroponics systems. Both of these methods provide automated way of delivering CO2 into the growing environment. It is preferable to use CO2 monitors in order to keep tracking the exact CO2 levels in the growing environment and automatically add gas, when it is necessary. However, such devices can be pretty expensive, so most people use more cost-effective methods, for example, timers.