i got a new tang and had it in qt for 13 days it seamed fine. It was eating and swimming and no signs of illness. I added it to the display tank and within two day it was dead. The skin on it was turning a whitish spotted color. It was not ich. The skin started to look like it was coming off and looked like sores and looked like the fish had been into a fight with something. They then went blind and within a few days all the fish in my tank were dead except for my lawn mower blenny who seams fine.Any ideas what it might have been. And how long i should wait to add new fish. My corals and nems are fine and water quality is ok.

