Whats making my clown act itchy?

So I have an adult occ. clownfish that acts itchy and uncomfortable. He acted fine yesterday and today he has something going on with him, but I don't know what. He has a few white things on him that look more long then round. It doesn't really look like ich, but its really hard to tell since there is so few of them and they are small. They don't exactly look like they are under his slime coat either, more like on top of it as when he swims they kind of flow around. In some ways they just look like particles that you find in the water sometimes. I did add a couple clowns to make a pair with my existing clowns, and I added a couple Banggai Cardinals, but its been a week maybe since adding them and none of those guys have showed any signs of anything at all. They look perfectly healthy at my LFS and they looked exactly the same now. I have had ich in my tank in the past (like 2 years ago), but it looked almost larger then this too me. So maybe its possible it popped up again somehow, but in some ways that's seems unlikely. I did put the clown (before he seemed itchy) in the sump for a few days (wanted to try to pair it) and its been two or three days since I put him back in the DT. The thing that gets me is that if I introduced something that I can physically see on my adult clown, why haven't I seen anything on my newish additions? Unless it was ich and it was in its drop off stage or something? The clown is just kind of hiding in his xenias today, not swimming around too much (which is odd). I haven't fed today yet so not sure if he is willing to eat either. This is so sudden and random that I am actually at a bit of a loss right now. He is in a 120 gallon reef tank with 1 white cheek tang, 1 Singapore angelfish (getting rid of), 1 male blue jaw trigger, 3 other clowns (going to get rid of two), 2 Banggai Cardinals, 1 sixline wrasse, 1 yasha goby. All other fisha are acting like their normal selves. I mean if any fish would have gotten something I would think the tang would be first out of all of them. I cant get pictures, its just to small to tell anything. If anybody has an idea I would very much appreciate it.