well its really simple, u take some corn meal about 3lb, sugar about 3lb, yeast 1 7gram packet(from walmart 3for 99cents) 3gallons of water. add all the ingredients together EXCEPT the yeast, heat them up to a low boil, then let it cool, AFTER its room temp add the yeast, then put it close to your grow room, fashion a cover over the bucket your using, run a hose too the plant, i dunno where on the plant to put it. but it will work for about 7days, its really not very hard to do, and u can distille the alcohol after, although i dont suggest this unless you know what your doing, bc u can accidentally get poison in it, also it dosent taste very good seeing how this is the shitty recipe for making alcohol...but it does produce a steady supply of CO2. bc the yeast eats the sugar and cornmeal and the byproduct is alcohol and carbon dioxide. you can tell when the yeast has died when you dont hear it bubbling anymore.
o yea, lol i dont really kno if its worth it 2 add CO2 to plants but i would think it is, bc they inhale that, but from what ive been reading it dosent do anything while the lights arent on?? I dunno hopefully someone can give use more input, on the effects of c02