My fish Paul, who recently recovered from a bacterial infection thanks to all of your help, seems to have a swim bladder issue. I feed him 2 times daily 3 pellets each feeding. He is staying toward the bottom of the tank only to swim up rapidly, almost vertical, to get air from the surface. He seems to be having trouble staying level from front to back. His rear end is sinking lower than the rest of his body. He does not seem swollen at all. In addition I was watching him earlier as he came up for air and before he reached the surface he released a rather large bubble from his mouth and then proceeded to the surface to breathe.