I made a sand filled tire in the run for dust bathing. It is under a tarped area but still gets wet. Yuck, and in winter it freezes. I want to put a litter box of sand inside the coop especially now that it is winter. The problem I have had with sand is that it is wet when you buy it and takes ages to dry out. I get the sand at Lowes or Home Depot. How can I get dry sand?