I think if the sump is large enough macro algea is a great thing, i have a seperate refugium with a small foutian pump that feeds it, and then it trickles into the main tank, I keep cheato, a couple kinds of sea grass and a couple of odd ball macros in there, it is full of pods micro star fish, etc, i have a small floresent light off a old tank sitting on top it used to be on when the main tank was off, for the last couple of years it has been on 24 hrs, macro is wall to wall in there