My male betta of two years, Mal, is having trouble swimming and he's showing signs of lethargy; he has no interest in eating, and is instead laying at the bottom of his tank, except for when he struggle to come up for air. He is also showing signs of fungal or bacterial growth that is isolated to his ventral fin (which I originally believed to be columnaris), and it looks as if he may be developing popeye, but I am not sure. He is normally in a 5 gallon tank with a water temperature of 76 degrees, but I recently moved him out to a tank with a much lower water level to accommodate his difficultly swimming. I treat him regularly with small doses of melaleuca/melafix in order to keep him as healthy as possible. Yesterday I begin treating him with Maracyn-two, assuming that he has a bacterial infection of some sort, with the hopes of curing him, but so far, there have been no signs of change.
I absolutely hate seeing my fish in this sort of shape, so any advice would be greatly appreciated.