Sorry to see that. Tangs are known to get ick. I have a purple, sailfin, hippo, yellow in my 180. Never had a problem. Good husbandry and diet is what I find the key. I also believe running a uv also contributes to itI also ordered 4 tangs. Babies. Added to a 20g long with new salt water mix heater etc... Anyway they broke out in what I think is ich and didn't make it. I did freshwater dip prior to entering qt. I dosed metroplex. It hurts.