in my 280 i have about 3' of sand 1-1.5 " of GEO marine CC on the bottom and 1.5" of argonite.
I'm going to switch and have 1" just to cover the bottom and the LS in rubber maid 55gal containers have them connected by bulkheads and have the other one with the heaters, and probes you knoe the drill.
Anyway
later