Is the pressure on your filter rising? Are you having to backwash? Try adding a little DE to your sand filter. Many of us do it, It may help you filter this out better. More about it here:

http://www.poolforum.com/pf2/showthread.php?t=3742

Did you ever find out how big your pump is? Some AG pools have a pump that is too big and too powerful and it just forces stuff through the sand without actually filtering it out.