Every time I increase the flow, the algae starts getting these long strings of algae shooting off of it. They seem to release some sort of seed too. The seeds look like the little string fibers that you get if you start rubbing a paper napkin on dry glass. There are lots of them too.
So macryn seem to have done the trick for you, then?
macryn seems to have worked, will see how things progress in the long term