Co2

Other than a Co2 generator and Co2 tanks, what are some of the best methods to get the Co2 levels up? I heard dry ice works. Any thought on that?

a yeast culture by your intake fan works great. some people are gonna tell you that unless you have the expensive setup not to even bother but it works.

ty, anyone know about dry ice?

if you have a good exchange of fresh air, you'll be fine. if you do some reading, you may find that you don't want to use co2. you have to have you environment under complete control to get maximum results from co2. otherwise you're pretty much wasting time and money. is your room sealed???