One of my six tiger barbs, a female, is suffering of dramatic swim bladder disease. A couple of days ago, I moved she and her five companions (3 males, 2 females) into a ten gallon tank to keep them from harassing my other fish. The pH is roughly 7.5 (but I'm gradually adding pH decreasers to fix that), the nitrite level is .25 ppm
, I believe; the ammonia level was at 0 last I checked. The water temperature is roughly 80-82 degrees. She is the only one sticken by this; the other fish are thriving (ie, chasing each other around etc). She floats at the surface on her side, still breathing as her mouth and gills are submerged. I've seen her try to swim down, only to float back up. Also, between her scales, it looks like a black lattice pattern; no idea where that came from and what it has to do with it all.
I've had ick, fungus, and fin rot with various fish, but this is the first time this has happened and that a tiger barb has gotten ill. (I've had them for almost a year now and this is the first time things have gone wrong.) Oh, and I cycled the tank for about 5 days before adding them all; she's been swimming strangely for about 3. Any ways to save her? My mother recommended that I just end her misery etc before the other fish get sick, but there's no way I can do that; I can't kill my own pets! Any ideas?? Many thanks--