It sounds like the beginning stages of ich. My clown did the same when I first got her almost a year ago. She got it REALLY bad. It's best and easiest just to quarantine the fish. Just go buy yourself a cheap little 10 gallon tank kit. You can get a setup that'll work just fine for around $40 just about anywhere. Bare bottom is best, so you don't even need to buy sand or gravel. I treated mine naturally, using garlic soaked shrimp, and some medications to her food, metrodizanole and focus. It took almost a month, but she made it. If you are going to run copper, which is very effective, you NEED to use the quarantine tank, because once you run copper, it gets into the caulking and plastics of the tank and will forever kill invertebrates and corals. Even if you don't dose copper, having them in a quarantine tank in a back room with the lights out and some pvc pipe and some fake plants to hide in creates an environment with a lot less stress. That will speed up the process. ANOTHER reason for QT is so that the parasite in your main tank can run its cycle without infected fish to host to. Ich can take around a month I believe. I left my clown in QT for 2 months just to be on the safe side. Good luck.