Visit http://www.zeobrite.com/Default.asp

They offer a superior alternative to sand in your filter see some details below from their web site:

Zeobrite®
Pool Filter Media
The Ultimate Media for Sand Filters:

   * Provides Superior Water Clarity
   * Lowers Total Operating Cost
   * Cuts Backwashing up to 50%
   * Reduces Chloramines, Odor and Eye Burning
   * Filters Particles Down to 3 Microns
   * Environmentally Safe, All Natural
   * Replaces The Sand In Your Sand Filter
   * Keeps Your Pool Sparkling Clear, Naturally
   * Saves Water, Energy, Labor and Chemicals
   * Easy To Install, Works In All Sand Filters
Typical filter sand is a round slick granule that filters by capturing suspended particles between the grains of sand. As the suspended particles build-up on the top 2-3 inches of sand, better filtration takes place. Sand media can remove particles down to about 40 microns in size. Zeobrite, on the other hand, consists of a rough angular surface in additional to its micro-porous structure. As water flows through the Zeobrite media, larger suspended particles are captured between the grains of Zeobrite, as well as, on its rough surface. In addition, water is actually flowing through the micropores of the granules allowing Zeobrite to remove small suspended particles down to approximately 3-5 microns. These filtering features allows Zeobrite to provide Superior water clarity from your simple sand filter.