My betta is always at the bottom of the tank. I got him back in January. He only swims to get air then he just lets his weight carry him to the bottom. He does have a bloated stomach, I am thinking maybe dropsy? I put him in a 1/2 gallon for now. I have a 5 gallon fluval spec and it wasn't until a few days ago he started acting like this. I put a little salt in the tank for him. What else should I do? I am sorry this pic is massive.