can anybody advise?, came home today and 2 fish were floating(dead) were fine this morning, done 25% water change sunday, treated the new water with tap-safe before adding to tank also been running 2 filters latley but took old one out on sunday, keeping discus, yellow fin tetra`s and a few big tetra`s (cant remember what there called ) 
also a few small catfish, everything else seems ok (the rest of the fish) anybody got any ideas? 
also a few small catfish, everything else seems ok (the rest of the fish) anybody got any ideas? 
