Hey guys, I've recently set up my biggest ever tank and i was looking around the shops seeing the Co2 Canisters etc.. I know what they do but there's one thing that gets me... If i do get one i'd have to minimise air stones right? well to increase the effect.. But won't Co2 be harmful to the fish... Like if you put us in a room of Co2 and took away some oxygen... Not really harmful... you know what i mean (i hope) I'd like to have it so my plants grow better.. But is it really neccesary for Java Fern, Anubias Nana and Java Moss? Thanks.