Thank you.. but I'm actually having a problem growing the coralline. when I first got the rocks (back in Sep) there was a lot more coralline on them. I cant seem to get it to grow. my CA is at 415-420, ALK is at 10-10.6. I think it might have something to do with the PO4 level its at 0.2. I use RO/DI and I don't over feed, I think it might be leaching out from the rocks because before I added them I never had a PO4 problem. as far as adding corals...... I would love to but just don't have the $$$ for the lights right now.