Hmmm - if that doesn't work, and isolating the fish in a hospital tank for eSHa 2000 treatment isn't an option, then NT Labs' Anti-internal bacteria or Anti-ulcer & finrot might be best. I've just lost a fish which had an internal growth/ bony scoliosis that burst through the flesh - at that point, an ulcer and accompanying fungus developed. If yours heads in this same direction, then I'd probably opt for the Anti-ulcer & finrot treatment (or have it to hand for this eventuality).