Purple tang white dots

[Jay Hemdal]

I just went to see what the fish looked after this night and there are no spots visible anymore. Is this possible if infected with ich?

Yes, that is possible. With the ich life cycle, the trophonts (the stage that makes the white spots) drop off and form the reproductive tomonts. When ich first starts up, the parasite is mostly in sync with each other, so the spots tend to all drop off at once.

Jay