As thor said I also feed my tangs romaine, but just like he said they get it along with nori, mysis, and all their other foods. I have a 5" sohal that came in to my tank about 6 months ago with a major case of hlle. He actually had very visable scars along with a 1" lateral "hole", along with a very pinched stomach. He was extremely mean and absolutely did not get along with my red sea sailfin. I was determined however to heal him. After about 1 month him scars started the dissappear and to this day you can't see anything. He is also one of the most passive fish in my tank to this day. I have him in my 125 with four other tangs with absolutely no aggression problem. My theory is tangs eat all day if they are not fed often and properly they will fight and become territorial. Before the tang police come out there is a 375 gallon in the garage ready to go for these guys within a year. Regardless I would like anyone to tell me between both his lack of agression and scars that I have not supplied this tang and/or any other tang the correct diet and or living conditions.