After 60 hours on bactrim, there is only a slight improvement. She is a bit more lively, she swims around aquarium rarely, sometimes presses on the wall, either trying to escape or just stay in balance. Most importantly tail is still significantly up, as if someone was pulling her by the tail up to the surface.
I think such minor improvement is rather due to better water in the hospital tank, rather than antibiotic. I'll be giving it 2 twice more anyway, since that's minimal curation time.
Meanwhile I am thinking, what should be next if this one does not work. Metronidazol, Kanamycin, Enrofloxacin? What do you think?
I should probably make a 1 day break too, to let her liver and kidneys rest for a moment.