After much consideration, I went with a sand floor in my coop and highly recommend it. We poured a footing deep enough to put in about 10" of riverbed sand which is very coarse and topped it with a couple inches of sandbox sand. You need to have a pile of extra someplace nearby to add. It is like having a big litterbox. The poo gets kicked around and coated with sand (I mix in some DE) and I sweep it into a dustpan with a piece of thin scrap wood I had laying around.