Jun 10
22
CARBON DIOXIDE
Nearly 50% of a plant’s dry weight is carbon, most of which comes from carbon dioxide in the atmosphere. Carbon dioxide enters the plant through stomata, or pores, on the leaves. In a process called photosynthesis, the plant combines carbon dioxide and water, using light energy as its power source, to produce simple sugars. Excess water and oxygen are released back into the atmosphere as byproducts of photosynthesis, and most of the sugars are stored in the roots, stems and fruit of the plant for later use.
Outdoor crops have a supply of air packed with CO2 that is constantly being refreshed by the wind. They also have rain to wash away accumulated dust and pollutants. Carbon Dioxide and Oxygen are both necessary to a plant’s growth: Carbon Dioxide combines with light energy and water to form sugars that are metabolized by the plant, while oxygen is used for respiration, burning of carbohydrates, and nutrient absorption in the roots.
An Indoor Garden must be specifically calibrated to replicate the outdoor atmosphere, and most Gardeners must take the time to set up an adequate ventilation system. Three factors effect air circulation,stomata, ventilation, and circulation.
Stomata are essentially a plant’s nostrils, they are used to inhale CO2 and release oxygen. Stomata can be clogged easily by dirt or other pollutants in the air, and pesticide sprays. To avoid clogging stomata, spray foliage with tepid water a day or two after spraying with pesticides, fungicides, or nutrient solution.
Air circulation is important because when air stands still plants can use up all of the CO2 rich air surrounding leafs in minutes, creating dead air zones. This can also lead to an easier infiltration by fungus and insects. To avoid this, you may want to keep a door or window open and/or install an oscillating circulation fan to keep up a constant circulation of air currents.
Ventilation is important to consider as well to get rid of exhaust air and bring in a supply of fresh air. An open window and a fan may be adequate in bringing in fresh air, but if no vent opening is available one must be created. Ventilation ducts and fans can be used to push or pull air into a room, and roof vents are a practical and discreet option as well.
Carbon Dioxide Supplementation
Carbon dioxide supplementation can be useful in some applications. If all of the other environmental factors are at optimum levels, such as light intensity, nutrient levels, temperature and humidity, increased CO2 can provide the extra material necessary to help the plant to flourish.
C O2 Tanks
Carbon dioxide can be supplemented in different ways. On a small scale, CO2 tanks can be used. Flow meters can precisely control the amount of extra carbon dioxide being released into the grow room, and timers can be used to stop the flow at night, when CO2 is no longer of significant use. For a 10′ X 10′ grow room, a flow rate of about 1 cubic foot per hour should yield excellent results.
C O2 Generators
For larger growrooms and greenhouses, CO2 generators can be used. CO2 generators burn natural gas or propane, producing carbon dioxide as a byproduct. Smaller units are available for 300-600 square foot rooms, and larger units offer saturation capacity up to 3600 square feet.
