I have a yellow watchman that has brown sploches on his body. They seem to be under his skin. Now on one of his fins appears to be something attached to the fin. Can't make out what shape it is, it is close to his body but only on the fin. That fin today is looking a little ragged. I have had him for 4 months. He is about 3.5 inches and very fat. Can you suggest what I might add to the tank to help him. I really don't want to remove him from the tank. Thanks for all your help.