Really it depends on what you decide to keep in there, what your tastes are and how much maint. you like doing. If its an sps tank, pieces of macro that die off make a pretty dirty tank for sps so the maint intensity will have to go way up if you keep those. Otherwise, lots of people do macro in the main display and keep it under control. There is nothing like an eel grass waving in the currents that is 24 inches long or an 8x24 dragons breathe.