Hi, I have a 56 x 24 display foot print, and was looking it to setting up a DSB, but have a few question I was hoping some one could help me with? I have calculated my main display to need 7-8 bags Caribsea Aragonite Oolite Sugar if it's 70 lb per cubic ft. 1, Do I have to use 4" or can I lower it to 3" with and adverse effects as it says it works at bed from around 2". Most of the documentation I have read suggested 4" 2, Can I add a coarser sand on top. Thin layer 1/2 inch say without impacting on the workings of the sand bed, Reasons for this is I don't want a sand storm. I am recycling my live rock which has been jet washed and soaked in RO water twice to make sure it's as clean as possible, I was hoping to aqua scape this on rods leaving 3" - 4" clearance on the base as not to compact the sand. With regards to cycling will I be OK to add the rock (soaked only in RO water) to the tank and then the sand and cycle the lot together, using bacteria solution? Or rock in tank only cycle first then add the dry sand.