My Yellow Tang died from a Primer they used on the basement floor, for the leveling compound to adhere. I noticed when they first used this, it got stressed. I immediately put a pump outside, feeding air stones. They didn’t tell me the second time they used the Primer. I checked to find out why, when nothing else was stressed. I found that Tangs Gill structures are finer, especially in Yellow Tangs, and the Tangs that have that body shape.