My suggestions is to use diy garf rock. you can use the frag plugs to make perfect dents to place things. You can even stick the mag float in it if you like. You could use egg crate and cement over that. Personally I'm using nearly a full sheet of egg crate and covering it in garf type rock for an uber nice back ground for my tank. You can even ues Rite dye to make it something other than brown/white. I saw a write up on it awhile back I'm just copying that from memory. and I've made garf rock using white portand, crushed oyster shells, and rock salt. The rock salt is used so that when you cure it in water for a couple weeks the salt disolves and make UBER porus rock fantastic home for critters and pods.
