All sweetlips that i have seen need a 150g
here is a description.
Spotted Sweetlips, also known as the Clown Sweetlips or Harlequin Sweetlips, changes color as it matures. As a juvenile, it has a brown base covered with large white dots with darker margins. As an adult, the body color changes to white with black dots.
A 150 gallon or larger aquarium is required due to its size and eating habits. It grows at a rapid pace to almost 3 feet in length. It needs a larger tank to provide it with ample swimming room and plenty of hiding places. If placed in a reef aquarium, the Spotted Sweetlips will eat smaller crustaceans, smaller fireworms, serpent stars, small snails, and polychaete worms.
When first introduced into the aquarium, it requires live food such as freshwater ghost shrimp, marine shrimp, or blackworms. Once it has acclimated, most marine carnivore preparations will be acceptable.