Thanks for all the suggestions! I had replaced two of the four bulbs in my fixture about a month ago just so I could put some low light lps in the tank. But in reading about cyano I found out that old bulbs can also contribute to cyano issues. So I have all new bulbs now, been cleaning the rocks and sand daily, and reduced the food input. I'm thinking reducing the hours that the light is on might also be a good tactic. I'm not growing any macro algae yet but was thinking I might start now and ya, definitely with the reversed lighting schedule. I'm not ready to give up on natural options yet but I'm aware of Chemiclean if it comes to that. I also thought about getting a sand sifter, one was on my original stocking list but I don't want to deal with having a fish dump sand on my corals so that's out.