afaid to find out the answer!

[bluemandj]

I have a blue tang that has been scratching its self against the rock and substrate. I figured it was ICH. I noticed that my dotty back and clown are also now scratching them selves.
Is this ICH? OR is it Marine velvet?

 

[bdhough]

Could be a number of external parasites. Just look at them closely the next couple days for spots or discolorations.