baby powder on a fish?

[daj0424]

I have had a blue hippo tang in my tank for almost a year now. It has had ich when I first introduced it and has been fine every since. Well, until yesterday. I noticed it has some white spots that look like someone sprikled baby poiwder on top. Not alot. just a very small amount.
I looked at a Beth's past tread of pictures of diseases and it doesnt look exactly like any of them, maybe fish stress, or a very small case of brooklynella.
I just introduced 4 green cromis so I know that has something to do with it. I wold take a pic but I dont have a digital camera at the present time. Can you give me some idea of what it is and the proper treatment. I would like to treat it in my display tank not a hospital tank but I do have some inverts and LR. Help.
Thank you!

 

[daj0424]

Let me be a bit more specific, I have seen ich before and this does not look like it at all. Ich looks like fine grains of white sand all over the bidy including fins. What I am trying to describe is flat on the bidy and looks like white baby powder on body, not on fins. 2mm in diameter. About 20 total spots on boby. Size of fish is 5-6 inches head to tail. Eats well, very fat. Because I have a moorish idol that tang eats small amounts of food 3-5 times a day.
The reason I am posting is because it doesnt look like previous cases of ich. Please advise.