My sister bought two clownfishes last Sunday. They were swimming and pretty active a few days ago until both of them stayed by the bottom of the tank. (The big fish) is breathing pretty heavily and is on its side. I have no idea what to do!! I've read and tried to find any information about what to do but can't seem to get anything. The big fish is breathing pretty fast and they barely eat idk what to do and im no expert. Any help would be nice and I can send them to my sister also if I need to do anything else, change tank or etc. Tell me