Wow, that was a great recovery, I thought he was a goner too. I had a fish that turned real dark like too, but without the clamped fins. I treated mine with Aquari-Sol. I am a real believer in that product. And what is great about it, because it is so mild, it can be used as a preventive, and also as a net dip, it also has the added benefit of riding a tank of pest snails.