Sorry but i made a mistake on my post saying 6500K, what i meant was 7200K or actinic lighting, hehe.
You might be right Jourdy, i was just talking through experience that coralline does not prosper even with low levels of PO4, i mean, they are THERE but not growing a whole lot even if there is minimal nuissance algae growth.
My coralline growth has red, purple and a bit of white. No green that i can notice though.the only thing that i dont like that much is that it grows on my sand as well. coralline grows under overhangs and caves in my rockwork too, and that recieves little to no light.
Oh and corals do LOVE coralline to grow out and crawl onto....