I've been reading up on the DIY forum of people who have used eggcrate with rock, foam, epoxy, and sand. It looks amazing once it has grown in -blends perfectly. I have seen many sps coral in there as well. Just looking to get some opinions in this forum as I am looking at making my eventual upgrade from a 90 to 150 with this project. Does anyone foresee a nutrient issue detrimental to the sps?