So I went to the LFS and had the phosphates and calcium checked. Phosphates were 0 and calcium was high which isn't bad thing he said. So I will wait and see what happens. I nervous because I introduced a blue hippo tang about 2 weeks ago. It was swimming around fine for 4 days and then it was gone. No clue where it went. I tore down the sump, lifted the rocks that I could and haven't seen it since. Just 3 days ago I got a cleaner shrimp. Spent 6 hours drip acclimating it and put it in the tank after. I see it swim down and then gone. Haven't seen that one either. So there goes $100. Currently I have 1 yellow tang, 2 clowns, 1 lawnmower blenny. CUC 5 conch things, 10 turbos, 5 blue hermits, 1 other snail that's starts with a "N" and 1 peppermint shrimp. All those goes and doing great! I am nervous about adding anything except for snails! I want to get a foxface but I don't need that vanishing as well.
6 hrs is a very long drip acclimation. Try 2-3hrs next time. It could have been ammonia burn.
I agree it's most likely just a new tank doing what it does. It should pass in time.
How long has the tank been set up and what size is it? Sorry if I missed that being mentioned earlier.

