That red algae you describe,does it grow like veins/spider webs across the rock?,does it feel coarse/not smooth or slippery?,does it grow very short,almost encrustnig like?
it grew smooth.....slippery feeling.........encrusting everything...........I swapped the lights around so that I am overdriving the 50/50s and in the last week 90%+ of the red algae is gone............guess that mean no more "standard" (HomeDepot) full spectrum lights.....