Thanks, McPuff. A few pages back, there was much discussion on the possibility of adding an Atlantic Blue Tang. That was my concern, that it would go through it quickly. But, that was also before I began dosing nitrate and iron. Now I have explosive growth, and I could use some help cropping it back. So I'm definitely leaning towards getting one. Keeping the macros cropped back might be the key to getting my seagrasses to take off. My biggest fear is that a tang might go after the grasses, once the macros are exhausted. But I think they'd be more interested any algae growing on the seagrasses, rather then the seagrasses themselves.
One other concern I have is order of introduction. My original plan was to add a tang last. Adding one now, second only to the Barnacle Blennies, could be problematic. But since it would be the only herbivorous fish, it might work just fine. A possible plus of adding it so early, would be its effect on later additions of schooling fish. Having a bigger fish in the tank will encourage schooling fish to 'stay in school'.