Not crushed rock, that's sharp. Use, Uh... pea gravel
So I should put smaller crushed rock or something over it?? I feel like a bad dog owner to see them going so slow. the rock i have is smooth river rock but its not like pea size its larger more like golf ball or alittle smaller.. the drainage is great and its easy to keep clean and free of flies.. I throw ridx down and once a week spray with odorban.. but just feel like they are miserable.. like they are walking on glass. LOL.. thanks for all the tips tho.. kinda glad i dont need to remove it cause its like 5inches thick.. and the sod thing would never go.. the urine would prob kill it..