I sue straw in the run on my patio but the run is covered, only the front of the run is open so not much moisture gets in there. If it does I rake out the wet stuff right away and put down fresh straw. They are on a concrete slab and the straw is much better for their feet then hard concrete plus the straw protects it from poo stains. The run out back is on dirt I use the grass clippings when I mow in there but if it rains again I gotta get it out of there before mold starts growing. I like the sand idea.
