Okay so I have a fish problem! I have a 29 gal reef with a 20 gal sump recently I tried adding fish to my tank but they do good for about a week then after the first week they show signs of ich then a day later a light colored rotting patch by the tail starts to form... this is the 6th fish that it has happend to. The only fish that are not affected by this is my yellow watchman goby and my blue damsel.