This doesn't line up with ich. The trophonts should remain on the fish for a minimum of 3 days. Not be there in the morning, gone in the afternoon. Are you sure it isn't just sand sticking to his skin? That happens a lot if you have a critter which likes to stir up the sand and then the flow blows it around your tank.
When i get home if I see anything on any fish i will try my best to take a good shot. But its not sand for sure because my tomato clown looks weird n eyes are cloudy. He is ashy color now and w/e is usually on them isnt on for no longer than a day or 2 but thr puffer sleays looks bad n his eyes are worse and he has been like this going on 3 weeks Sunday. Idk how he is still alive esp without eating. But at this point im more worried about my other fish than him *sad to say*.
But my niger trigger for sure had a few specs on him this morning and when i went back home to check on them in the afternoon it was gone.
I want to cry bcuz i dnt want anything to happen to any of them esp. My black damsel :/ but i will post something asap