I just bought a dogfaced puffer about two weeks ago and tonight right after eating he just randomly puffed up. Now I have heard that is bad for them, but I wasn't sure if it was true. What causes puffers to puff up? He spit out some food after he deflated, do you suppose that had something to do with it? I recently put copper sulfate in the tank from him having a TINY amount of ick on him. Does copper doing anything funny to a puffer? Also I had to put in some fungus medication for the clown, would that have anything to do with it?