The Purple Tang (Zebrasoma xanthurum) is a colorful, hardy and semi aggressive tang that will add color and beauty to any aquarium, whether a fish only (FOWLR) or reef tank. They are reef safe, and need a balanced diet, but heavy with algae. They get to a maximum of 10", but usually max out at 6-8". It is recommended that they are one of the last fish added to your aquarium, as they are territorial, especially to other tangs.