Diatomaceous Earth

Also Known As:

Diatomaceous Earth is naturally occurring, ground, sedimentary rock that can be used to filter pool water.

In a pool filter, DE has been crumbled into a fine powder. It is made up of the fossilized remains of diatoms, a microscopic, hard-shelled algae. When used as a filtering substance, diatomaceous earth or DE can filter out particles that are much smaller than a grain of salt.

Because it is made up of hollow particles, DE has a high porosity, making it an excellent filtering medium. Deposits of DE are varied, featuring a variety of compositions of fossils, natural clays and minerals. In addition, the deposit’s age dictates the amounts of silica found. The special of diatom also varies from deposit to deposit. However, the shape of the diatoms do not affect the performance of the DE as a filter medium.

DE can be purchased at any pool-supply company. The powder is added to the pool’s skimmer and pushed through the filter by the pump. It then lodges in the DE filter grids. DE powder should be added after a thorough backwashing to insure that the pool water is being filtered properly. Once a year, a DE filter should be broken down and cleaned thoroughly.

Because DE can cause clogs in waste-water systems and damage to natural streams, DE waste water must be disposed of properly. Pool owners and managers should consult their local waste-water guidelines for regional-specific regulations.