I am rethinking my run floor. Coop is deep litter method, which works so great, but my run, I have alfafa hay, and now I have flies like you don't even know. this post isn't about the flies though. I am thinking about sand. Tell me your success stories when using sand. How deep? Where did you get it, what type is it? Anything I need to know that could be dangerous to my flock as far as sand goes? We have an additional coop and run that isn't quite finished yet, so want to do it right right off the bat plus change out the current run to sand, if that's the best idea. thank you!