I bought a baby gold saum near a month ago, I picked the one with the longest fins hopeing to get a male , It's fins where ripped by the other baby saums in the tank at the store, his (possibly) fins have not healed. and he is still active and eats regularly. I was wondering if I should treat the tank with melafix, but his tank mate a near full grown jack dempsey seems to be fine , will melafix have a negative effect on healthy fish? ALSO My jack dempsey has never shown any aggressive / territorial behaviour to his tank mate and sometimes appears to bring food to the gold saum, is this odd behaviour for jack dempseys?