This just happened today, and I noticed 5 minutes ago. I have noticed previously that the fish looks rather bloated, and now that we realize it it wasn't pooping. However, today we just saw it floating upside down, and having trouble swimming and barely moving. At first I thought swim bladder, but now I don't think so. I don't have any peas or safe salt, so my brother wants to euthanize and hope for the best.
Edit: The picture is a picture I found on the web, but it looks exactly like what my fish has
Edit: The picture is a picture I found on the web, but it looks exactly like what my fish has