I have added sand 3 times during the summer( like 6 yards ) each time to both my runs . everything looks perfect until it rains , then yikes ... Chickens are scratching making holes ( naturally ) when it rains , the holes are full of water and creates oders . It would be a constant thing of being out there to rake them out and level again . I also put 1/2 one run under a large vinyl tarp , but even elevated peak , belly's out in the middle . Any suggestions ?