FYI once he finds a spot in your tank.
You probably won't even know he's in there. They are solitary and will hide out.
I put a 4" in my tank basically forgot about him in time.. moved tank there he was 8"+
Update : healing nicely. Haven't seen him eat, but he is being shy. I took out his log that he was hiding in to get him used to his surroundings (in a 125 by himself waiting for slow addition of oscars that are growing) ... Bad idea ??