He's been twitching a lot, rubbing himself on the gravel, and has a clamped dorsal fin. The side he's been rubbing against the gravel also has a small patch of what appears to be white fuzz. I'm not sure if it's a fungus or what but i want to clear it up asap. He has a healthy appetite and is still active.
Any information would be much appreciated,
P.s. I recently took back the jack dempsey who shared the tank with him because he kicked his ass and nipped at him a lot... so i'm thinking this could have been the initial source of entry for whatever it is.