New to the saltwater hobby, so hopefully will find an answer here. I have had my tank for about 3 months running now and have been checking water quality weekly. I added 2 clowns which have been doing well for over a month now, and just picked up a yellow tang from my lfs earlier than I wanted due to the shortage. I just got back from work tonight and noticed the tang had big dark spots on both sides right in the middle of it. Is that just food or something more? I've only had it for 5 days now and this is the first it's shown up