Well after slogging though this huge thread I would like to start by saying my Silkie run use to be shavings and now is 100% sand. One thing I dont see anyone mentioning is for health reasons. Silkies and other gamefowl (red jungle fowl, green junglefowl, peacocks, ect) are prone to respitory infection.With dirt/shavings as a floor I have found mold and mildew in cedar/pine shavings. this tells me they do not dry fast enough and as they decompose(deep bedding method) its been my experience my birds sometimes develop respitory issues. Sand (if course enough) does not retain moisture and by itself has nothing that viral or fungal can cling too. I think some people may live in climates where sand may not be optimal, but I suspect for the health of the birds.... if you can use sand, I would do so. Especially around feeders. My birds scrape food out of the suspended feeders on the ground. when I use to go in with a shovel and "turn' the dirt I found most of the mold/mildew 1/4"-2'" below the feeder leading me to believe if they were eating food they had dumped onto the ground, they were possibly eating infected food.