Mine is sugar-sized, nice and white, and I have two Tunze 6105's in my 90 gallon. Once the sand becomes established, over time, bacteria helps to hold it together a little bit. I don't run a DSB, but rather a shallow 1" - 1-1/2" deep sand bed and it has to be stirred and raked on a somewhat regular basis. I also keep some nassarious (sp?) snails in there to stir it up and I adjust my powerheads so they provide great flow for my SPS corals without causing a sandstorm.
I have a pair of diamond gobies in a 125g that keep a 1-2" layer of CaribSea Special Grade sand pearly white and for the most part detritus free. However, about once a month I have to push the sand away from the glass and scrape it, as I eventually get algae growth between the sand and the glass.
Ok so you recommend gobies, cool.
Got any nass in the tank also?
Also, would a phosban reactor or biopellets make a difference?
I take a multifaceted approach consisting of fighting conch's, a sand sifting star, nass snails, engineer goby, a tiger tail cucumber, and manual siphoning of the sand bed with each water change.