One of my baby clowns who is about 9 months old has been lying on its side and breathing rapidly for 24 hours. See video. I have done a freshwater dip but I don’t think it’s a parasite as the other 30 fish are all ok. I bred them and have introduced no new fish. He seems a bit better than yesterday as moving a bit more but he’s definitely not right. Any suggestions on how to help him?