Rapid breathing,Is it ich?

Hello, I have had a kole tang in my 40 gallon for approximately one month(he is small and I am getting an 80 gallon frag tank 4ft by 2ft in approximately two months). Recently j noticed he was breathing heavily, I initially though ich. However he is not scraping against rocks, and I can not see for sure if he has white spots because of natural spots on his head. I did see one spot on the fin though. Also the tang has been rather confined to one part of the tank. I believe I stressed him out too much, due to recently reaquascaping and taking out the sand bed (now bb). I haven't gotten him to eat anything I put in the tank, but he has been grazing on the rocks and glass. My fear is , if it is ich, that it could spread. Only other tank mates are a snowflake clown, fire shrimp, and few corals. Everything else in the tank is flourishing. (BTW I have lots of surface agitation, an open top tank, and a sump so I highly doubt Oxygen problems) any help would be appreciated, also tips for feeding would be good. I have tried garlic soaked seaweed, caulerpa, and new spectrum pellets.