Function

• Plants combine carbon dioxide with water, light and nutrients to create energy in the form of sugar. In an enclosed grow room, you must replenish the carbon dioxide as it is used so the plants can continue to grow.
  
  

Homemade CO2 Systems

• A homemade yeast-based generator is the simplest and least-expensive way to add more carbon dioxide to your hydroponic garden. Place one teaspoon baker's yeast and two cups of sugar in a plastic water bottle. Fill it halfway with warm water, tighten the cap and shake the bottle vigorously to combine the ingredients, then remove the cap to let the carbon dioxide escape.
  
  

Commercial CO2 Systems

• Large hydroponic gardens may require a commercial carbon dioxide generator to keep up with the plants' consumption. Basic systems include the generator and an injector to distribute the CO2 throughout the garden. You can also add a CO2 monitor to run the generator whenever the carbon dioxide levels drop below a specified point.