I got a nice looking large angelfish yesterday from my lfs that was going to be put down. I asked to take him home and see if I can help him first, so he's currently in a cycled, empty 8 gallon with a sponge filter. I'm hoping you guys can offer some advice for treating him.
He's stuck at the top of the tank, floating around on his side. He looks quite bloated. I've seen fish with dropsy before, but I don't think he is suffering from that; his scales aren't protruding and he looks quite alert and not distressed. The fish I have seen with dropsy looked severely distressed and unwell and that's not the case with this fish, in fact he looks quite interested in his surroundings and doesn't have the "glazed-over" eyes that I've seen on fish who are on death's door.
I offered him a bloodworm last night (not to actually feed him, just to see if he was interested) and he ignored it, so I doubt he will eat de-shelled peas. I'm thinking he's probably got some sort of constipation/swimbladder issue, so I'm wondering how I might go about treating that. I've read online that adding salt can help, but I can't find an actual explanation as to why so I'd really like it if someone can explain to me how salt may or may not be able to help him before I go ahead and try that.
He does have a bit of fluffy cotton on one side of his head as well, though it's small and I'm thinking the swimbladder/bloat problem should get treated before I deal with that.
Any advice would be much appreciated