I recently bought a blue hippo tang from my local fish store.. It was in a copper system tank.. I brought it home and acclimated and it was doing great for about a week and then it got what I though was ich.. I started treatment and seemed to have cleared up. I want to add though that none of my other fish got it.. It died yesterday after it started clearing up. The fish was eating but you could tell it was thin.. I tried upping the feedings but apparently unsuccessful. My question is, is it common for blue tangs to get ich?