Definitely rehome. Scats get big, and I think they school, so you might have to buy more scats if you kept this one.
Also, as they grow, they may eventually need full marine conditions, and their appetite for plants wouldn't allow you to have a nice planted tank if that's what you want.
i have four scats and they are in full sw, one other thing is that they are like big puppy dogs so they investigate everything so it has to be a rock only since they ate my feather duster coral and decimated my other one i tried to keep
mine will be going into a 168 fish only tank in days to come