We tried a deep layers of sand in our first run. It just didn't work out. The run was about 10x8 for 6 hens. I had read that sand desiccates the poo, but it created another issue - DUST. The girls loved the sand for dust bathing, but it would get messy really quickly. We couldn't keep the dust...
I have a very lovely Blue Orpington hen that needs a new flock. She is a gentle giant. 2 y/o and lays about 2-3 eggs a week when not molting (she's wrapping up her molt now).
We really love her, but had to downsize our run in order to make room for extensive concrete and home repairs outdoors...