Reading this thread, it seems that most/all that have sand in the reef tank, do so for aesthetic reasons only. Does no one do the "deep" sand bed anymore? Perhaps I am showing my age but 4.5-6" of very fine sand, with a thin layer of coarser sand on top, to prevent it blowing around? Done correctly, one would never disturb it and enjoy all of the inherent benefits. To me, a "thin" sand bed, offers no denitrification benefits and is just a detritus trap.