abfleck has had him in an open top tank with no problems. I decided to make a lid w/ eggcrate, took me (and my wife) about two hours to get it perfect. I'm sure he can find away out but i'm hopping the eggcrate will hold him in until he's happy with his setting.
I'm surprised on the fishes reactions to the new eel. My yellow tang is bullying him, anytime he peaks his head out, the tang just sits there and shakes it's tail, doesn't let the eel come out anymore than it's already out. All the fish seem to be slightly aggressive towards the eel, I would have thought they would stear clear.