Hey Stinky! Very very cool fish! I would love to have one...has your's grown quickly or quite slow? If he is only the size of a toonie must be fairly slow growing. I would LOVE to have one in my FOWLR but I do have a couple of corals in there (frags from my reef) that I would be worried about him touching. (Yeh kind of defeats the purpose of a FOWLR)
Also the idea of him "expiring" and wiping out the tank is a bit of a bummer....what fish do you have him in with?