Advise for internal bacterial infection

[KJoFan]

I have a discus with an internal bacterial infection. It's got a bloated belly which epsom salts did not take care of and occasionally secretes white pus. What antibiotic should I go with to treat this effectively? I have very hard water if that makes any difference on type of medication.

Thanks.

ETA: Should I isolate the fish and treat or treat the whole tank? No one else seems to be showing symptoms at this point.

[brewmaster15]

Hi Karen,
I'd separate the fish.. meds to use...

kanamycin sulfate (jehmco.com usually has it..) is my first choice, second would be maracyn2 (minocycline)., and third would be Oxytetracycline.
hth,
al