No its perfectly fine in a reef system. I used to have one till I woke up onemorning and it died. I don't know why but it just died for now apparent reason. I have a purple tang and a powder blue tang. Just watch out the tang family can get ick vary easy. I best thing for that is a UV sterilizer and a cleaner shrimp or cleaner wrasse. I have both and the wrasse does his job better.