I have an injured goldfish, what happened, and how do I care for him?
I have a single goldfish, around 4 1/2 inches long and two high ( including fins). He is in a five-gallon tank with a short, long fake rock and roman ruins, as well as a pipe leading up to the filter. These do make it a little cramped, but it doesn't seem too bad. I just noticed that he has scales sticking out of his side, which look like they're being pushed out by a translucent-ish shpere, which was large and round a little while ago, but now looks a little deflated, and almost clear in one spot. I just changed his filter, put in the proper amount of stress coat, and am planning to clean the tank shortly. What's going on, and how do I remedy it? It's pretty urgent, and any help is greatly appreciated. Thanks!