White spot on Clownfish in mature tank

[eternitybc]

And now it's gone again, so whatever it is, is using my fish as lunch. Ich? Although it looks kind of big for that?

[George]

It doesn't look like marine ich from the size and shape of that thing. Most likely some kind of parasites. I would try fresh water dip first. Google the protocol or let me know if you want the details.