What is wrong with my clown?

[squid row]

About three weeks ago I noticed a slime like substance on the clown. In the pic it looks like dots, but it really is more slime like.

A blue tang had the same thing but it went away after two days but the clown has had it for weeks.

He is acting totally normal. Eating and active.. no change in demeanor at all.

Any ideas? I looked through the fish id thread and did not see anything that covered this unless I just missed it.

Tank is FOWLR right now but I did add a BTA about the same time this slime type thing started to show up

Any advice?

 

[Cdogsailr]

Not very noticeable in photo? Keep in mind that clowns have lots of slime on them, about 4 times any other fish. This is what allows their love affair with anemones. They'll even gather more slime from the anemone itself when bonding. Any update?