Help! White patches on fish

[jennytheleopardgrouper]

I just noticed about 45 seconds ago that both my yellow-tail damsel and sulfur damsel have white patches on their sides. I first saw the yellow-tail damsel, and thought it looked like a bite-it's bright white, a few millimetres wide and just looks like his scales have been nipped off. But the Sulfur damel has a much larger spot-about a cm and it's not as white. Larger than all my other fish's mouths. It's just a flat patch, and not bumps like ich.

I just added a new coral last night from someone else's tank, but it was FW dipped first.

In the last week I've been using new products in my tank. I don't know if one may be contributing to this problem. The products are AragaMilk, Kent's Phytoplex, and iodine. Tank temp is 79, and all parametres good, although I'll test again.

Everyone is acting normal, and eating well. Any ideas?