Diatomaceous earth (D.E.) filters have always been recognized for providing the cleanest pool water. And, cartridge filters are popular for their convenience and easy-cleaning features. Now Pentair has found a way to bring you the best of both. The Quad D.E. filter features four easily accessible and removable D.E. cartridges. When water passes through these cartridges, microscopic impurities like dirt, algae and some forms of bacteria are filtered out, giving you water that really sparkles. The four-cartridge design greatly increases the filter’s internal surface area, meaning much greater cleaning capacity per cycle. And cleaning couldn’t be easier. In fact, you have three options…backwash and recharge like a traditional D.E. filter, remove and rinse off the cartridges, or simply remove the lid, leave the cartridges in place, open the drain plug and rinse.