Help, Yellow Tang has tiny black dots on its body

[Drock169]

Protomarin Coral by aquarium munster, reef safe product for treating ich, just make sur eyou follow the instructions.This product will only work if the ich is just in the early phase

[Delphinus]

I'm not sure if that's about ich though, or for black ich. "Black ich", which is most assuredly (I think anyhow) what he has on his YT, is a flatworm and not a fluke. (It's a bad name, I guess people just call any kind of spots on a fish as "ich".) Black spot disease which looks like ground black pepper is totally external and large enough that the cells lyse under osmotic pressure of FW. Real ich (aka Cryptocaryon) will not be knocked back at all by a FW dip. The dots that you see in "real ich" are little holes, the dots that you see in "black ich" are the bodies of the flatworms themselves. They will literally fall off after a FW dip.

As to QT'ing the rest of the tank .. if it was me, I'd leave them if they show no signs of spots. Catching and dipping a fish is stressful, I'd only do it if needed. If they are established and healthy they likely won't get spots.

At any rate, FWIW, my YT only needed one dip and the spots never came back and never showed up on any other fish. As always maybe YMMV but that was at least my experience.

Good luck!