Yes, a refugium is a good idea! I run with chaeto and 3X per week I shake the algaes to liberate "mulm" to feed my corals with that bacteria mulm. Eventualy I put some algae on display tank for the happyness of my TANG's. Lights - I have one bulb 6500k and one bulb Grow light (450nm + 660nm) I don't see to mutch difference in grow. And the final consideration is No3 and Po4 reduction safety, because Algae will not remove NO3 and PO3 aggressively like some medias. So I only use medias when needed! IRON - is very important to supply some chelated iron if you run algaes on refugium, just a small quantity of iron is enough (I put in Calcium baling) - Do not try to measure iron to some value, because iron will be consumed/transformed very fast, so if you dose is OK, more than 0,15 ppm of iron is poisonous.