It is in a 300 gallon tank now - it is wider than the tank...
I've got a 300 gallon stock tank outside with some turtles in it. We are thinking of putting the turtles inside the aquarium and putting the fish outside, at least the stock tank is round and he could turn around.
Give him to the Houston Zoo or the Aquarium. I know they have both taken more common large catfish before. I think they would be interested in something like this. I guess you have the largest one in Houston. Mine is probably second though at 21 inches. Too bad they can't be friends.