So I have a 10 gallon tank with two pink gouramis, two tiger barbs, and a green barb. There's no water problems, and I do a 30% water change once a week. Anyway, I noticed last night one of the tiger barbs was sitting vertically. It was the middle of the night, so there wasn't too much I could do. Today, I noticed his fins were damages pretty badly, so I put him by himself and added some salt and Melafix. He can't swim or float very well, and looks stiff like he's dead, but isn't. Any information or advice would be greatly appreciated.