I always hate it when people don't update threads to say what happened, so.... it worked!
I left the CO2 high, reduced light to 1 T5 bulb (which slowed, but didn't stop the algae), and then I introduced more fish and started dosing Excel. I'm going to look into other fertilization schemes, but just these minor changes have made a huge difference.
Yeah the glass is cleaner, but look at the substrate and on the plants themselves. Drastically reduced algae.