PLease help!! My new betta boy arrived with a lump on his spine, which grew and grew. Then his dorsal fin shredded almost overnight and disappeared. The rest of his gorgeous finnage seemed to disappear shortly after that. I keep him in a heated, filtered 5 gallon tank alone. Water readings are normal. I do weekly changes (25% or more) and gravel vacs. I treated him with Trisulfa (ran out of Kanamycn and no one sells it anymore out here). He showed improvement after 2 treatments so I stopped. Fin rot started back again and of course, no one around here had any Trisulfa so I treated him with tetracycline--he's shown slight improvement. I don't know what to do now! Everything I read gives many options for fin rot, I guess it was bacterial since there were red streaks in his fins but they're gone now. Should I go back to the Trisulfa? Continue the tetracycline?