Melody, not to be mean, but you have no business giving advice to others about keeping monitors. You bought a baby and are keeping it in the worst possible enclosure. If you actually knew anything about them you wouldn't be keeping him in an aquarium on newspaper.
Did you do any research at all? Ive seen advice given to you on this forum. Did you just blow it off? If so then I wouldn't worry about how big he could eventually get....