decorator crabs are NOT reef safe. i had one for about 2 days and took it back. they WILL pinch off pieces of corals and anemonies and use them to camoflage itself with the reef. they clip off a piece or two and stick it to thier bodies and you hardly ever see them until it is time to re camoflage, then it is another coral that gets chopped up. they look very cool, but are more for a FOWLR tank. hope this helps in your decision.