Terrible idea, when I worked at a pet store we had a wolf fish and the person who worked the fish section told all the workers do not put your hand in the wolf fish tank, use a longer brush or a long net, but sure enough one of them stuck her hand in the tank because she dropped the tongs used to feed the fish into the tank and the wolf fish bit her, there was blood trailing down the aisle. Wolf fish are usually housed alone for that reason, plus wolf fish get about the same size as a discus would so they'd view them as food. A wolf fish (assuming you mean the rainbow or red hi fin wolf fish) get to be 10 inches or so, I'd recommend a 70 or 90 gallon because of the bioload they produce, though a 40 breeder could work as they aren't overly active fish