Is it a combination of water parameters and food that causes HLLE? I have a Sailfin Tang that has very small spots near its eyes from time to time and am afraid that maybe it may need something else in its diet. It has never progressed past barely noticable spots, but I have seen some bad cases of HLLE at the LFS and absolutely don't want that to happen to my fish. Currently I feed a variety of frozen foods and Formula One and Two Marine Pellet. I have been feeding Formula Two the most since it is supposed to be for herbivores and my tang eats most everything before the other fish have much of a chance. Luckily it can't consume all the thawed frozen food that I shoot around with a baster. Does anyone else have a tang that just doesn't want any other fish to eat ever by darting around the whole tank eating every scrap of food including bits sucked to powerheads?