A kole tang is going to get about 7 inches, and needs a 75 gal or more tank. This is what it says on ***********....
The Ctenochaetus strigosus grows up to 7 inches. The Kole Yellow Eye Tang prefers a tank of at least 80 gallons with plenty of places to hide & swim. The Ctenochaetus strigosus is an herbivore and likes to eat marine algae, zucchini, brocoli, mysid shrimp, Spirulina, lettuce, seaweed, sponges, and other meaty treats. The Kole Yellow Eye Tang is a medium maintenance fish and may act peacefully toward other fish. It might not get along with other tangs. Reef-safe. Keep water quality high (SG 1.020 - 1.025, pH 8.1 - 8.4, Temp. 72 - 78° F).
It also says that they are peaceful and are reef safe. They should also be kept singly, and not in groups.