Is the pool cloudy mostly in the deeper part of the pool? I suspect that with your size pool you have one return and one skimmer and no floor drains, is that right? If so, then you can do two things to help clear the cloudiness in the pool -- 1) brush the pool to stir up what is on the bottom to help get it to the filter and 2) point the return diagonally down and to the side to create a circular swirling effect that can bring up some of what is in the bottom of the pool to the surface. I'd continue to use DE in your sand filter, but you've got to get the cloudy water to the filter to clear it. I'm also assuming your filter is actually working properly -- if the sand is channeled, then that won't work properly to filter (though if it were really bad then the DE that you add could come back out the return).