hello flameangel...this guys are only fish only tank safe...no reef for this guys...they will much on your coral...but they are interesting creatures...hardy as well...mine does lots of good cleaning for me!!
Mine does fine in FO. As stated above, no reef for them. I use to feed mine a small piece of shrimp once a week, now I let him collect algea off the tank walls.
I don't have one and but what I have always heard was that they were one of the most agressive of starfish. But......then I came across this site which says they are reef safe.??? http://www.marinedepotlive.com/1303634.html
I guess you can try to see for yourself but do you want to take the chances?
As with all fish and inverts it really depends on the personality of the one you get. Some might like the taste of different types of corals while others don't. I wouldn't take the chance of putting one in a reef though. Also harliquen (sp?) shrimp eat them just in case you have one.