I have a 12'x8' run filled with 3+ inched of sand in June... Housing 6 chickens and 3 ducks... The problem is that the sand does not seem to be draining from the areas where the ducks play with their water. I don't know if it is because it is mixed with their poop as it is impossible to rake it all from the muck. So it is constantly wet and even worse now that it is freezing over night and thawing during the day. Is there a better medium? Help!