Hi New to this site! Looking for some help with my co2 in my tank! Recently been givin the fluval edge as a present and set it up as a tropical tank.All the test from the water are perfect but the fish seen to be uncomfortable in ther and are swimming at the top of the tank 90% of the time leading me to think its the co2.Have spoken to a few people about this problem and they all blame the tank due to its small surface area! They were very critical about the tank and suggested i take the tank back blaming its terrible design faults! I am new to fishkeeping and would really appreciate anyones advice on this matter! Kind Regards Deco