something is wrong with my tank. I had a silvertipped tetra that had it tail pulled/ripped off, a loach that somehow got huge scratches on his face and now a danio whos bottom jaw is hanging on by a thread. The tetra and loach died, but the danio is still living. I have a reg 55 that all those were in. I have 2 pengiun biowheel 200 filters, a 400 watt heater (dont know the brand) plastic plants, driftwood, smooth river rocks, and a course sand substrate. Would any of these cause that kind of damage? What should I do with the danio? Im really frustrated because I try to do the best for my fish and they just seem to keep dying
