Yeah, another plus for only have four rocks - removal of rock for pest control! I also like the branching red algae, however, it is small and looks tasty (I just don't have any vegetarians apparently).
I currently don't have any macros in the fuge, I plan on getting it filled with chaeto soon. There is some helimeda and Caulerpa taxifolia (I think) on a rock in the display. The only thing is that the nuisance crap is growing faster than the macro right now, and is slowly taking that rock over. Would manually scrubbing this rock help in any way? I could do that in the buckets of water I take out for a water change...I tried sucking it off the substrate with my gravel vac, but it was well attached, so that didn't work (just ended up burying most of it).
I currently test for PO4- and NO3-, and neither are out of whack (0ppm and <10ppm respectively). I run the lights for about 12hrs. and can cut that back to about 8hrs, but that probably won't have much effect on the nuisance algae. I also have the feeling that this is also part of the cycling of my tank, but does three months seems a little long?