So I have a 90 GALLON comunity tank w\3 iridecent sharks, 20 or so rasboras, and 10 tetras.
yesterday I did a 60% waterchange, removed the old rocks and sand, and scrubed the algae off the tank (no chemicals used)
filled the tank back up(used conditioner)added a new large Bala and two small plecos. This evening I notice that all the fish are at the top gulping air, the water is really cloudy and my filter stopped(I have a large cannister filter) So I change the filter and go out for dinner. When I came back all 9 Balas were dead.... what the hell happened???