True. Algae out is nutrients out, even if it ain't so pretty.I have chaeto in my make shift refugium in my redsea e170. I get green hair algae with it all the time. As far as I am concerned I just need to clean it up a bit every week. In my opinion the point of the refugium is to take extra nutrients out of the display, so isn't the "pest" algae doing that too?
For what it's worth, my Gracilaria did best when I had a circulation pump in the refugium constantly turning it. Although it forms "holdfasts" (whatever the equivalent term for Rhodophyta is) it seemed to appreciate the tumbling and it made the GHA harder to adhere, but the pump was constantly clogged, even with a prefilter.