Brewer's yeast CO2 generator

I have to agree with homebrewer. The 2l bottle does work for a small closet or freezer grow but anything bigger than a 3x3x6 space it is a complete waiste of resources and time. I use 20lb co2 tanks which only cost me $16 to swap out every 5 weeks, granted I only run them for 30min a day and my ppm's only reach about 1250 but it is well worth it to my ladies. When I used the diy setup I had to have a 55gal drum setup for fermentation and it was an extreme hassle to maintain and the cost was a lot more than my investment and maintenance cost of the tanks and the regulator.

I don't see how you can really go wrong adding co2 to your grow environment, especially considering this is made out of things most people have laying around the house anyways. It may not technically be as economical as a propane or natural gas powered unit, but it also doesn't cost $500+ to set up, and it doesn't add another possible catastrophic risk (pressurized fuel) to the grow room. It sucks because there are serious drawbacks to all of the common co2 set ups. I think I may end up going with the tanks until I get completely sick of lugging them around to get filled constantly.

I say give the yeast thing a shot, if nothing else it will show you the importance of co2. Adding co2 to a micro grow also makes sense because it will help the plant tolerate higher temperatures.

I have used a 4X10 room with three- four 64 oz bottles with 3Tbsp yeast and 3 cups of sugar. Change when no fizzing occurs when shaken. I have a CO2 monitor to check the concentration, and can hold rates of 900-1200ppm with this system in a well sealed room. To deliver the gas drill a few holes in the cap if you don't use the balloon method stated above.