ive a 6x2x2 tank our pride and joy so our water is tip top all fish healthy[arrowana,oscar,jag,bala and catfish] today i bought a large tinfoil and another bala from seperate tanks both looked healthy but tonite both are dead :[ they have a slight red appearance to the belly and a touch of a white film the only thing i can think of was my temp too high? it was 80 when i checked a bit too high ! all my other fish look great do you think this killed my new 2 ?