Hello all, I have a question about the effects of bubbling CO2 into a cannister. Is it normal to have some clouding? My 20 gal. is running on a Fluval 103 with different bio-medias, and there is a cloud that I can't explain. The worst part is that it's *just* noticeable, and it isn't affected by water changes. Could it be yeast contamination? Any thoughts? John