I also have a covered sand run and love it, i found a dog pooper scooper that lets the sand filter through - like a kitty litter scoop on a pole. We scoop the big poops nearly every day, it takes just a minute- but we don't think of it as cleaning - more like harvesting manure for our compost and garden. I add DE spring-fall to keep flies/mites under control and control odors. if I had a dirt run I would add mulch or leaves and rake it all out in the spring for the garden and replace.
