I second the idea of splitting the bunches in half again. It takes a long time to get established, but when it does it grows quickly. Especially in substrates like what you have.
How're your PO4 levels looking?
If you can spare the cash, Marineland makes a mod for maxi-jets to turn the pump into a more gentle circulation machine akin to Korallias. That might be a good option for you since you've already got the pump. Google Maxi Jet Circulation Pump.