DE Filter

A DE filter uses diatomaceous earth to purify pool water. When in good working condition, a DE filter requires less backwashing, perhaps only once a month. It is capable of filtering very small particles.

DE powder is added to the skimmer, which pulls the powder through the water and into the filter tank positioning it on the septum.

The DE powder is dissolved in the water and then trapped by grids within the filter, where it filters out impurities in the water. The pump should not be operated without DE powder coating the grids. In this case, the pressure will rise and the flow rate decrease. This can lower the pool’s water quality.

DE filters should be inspected at least once a year. A torn filter septum can be replaced or recovered. When adding DE powder to the skimmer, make sure that none is going back into the pool through the returns. If this happens, the grid may be torn.

In addition, a DE filter system should be taken apart and cleaned once or twice a year at minimum, depending on the kind of DE filter installed. Turn off the pump and drain the filter. Remove the grids and spray them with water. For a more thorough cleaning, soak the grids in a large container of water and filter cleaner. Rinse before reinstalling the grids.

Pools with DE filter systems may not need to be backwashed as often. However, because DE waste water can cause clogs in waste-water systems, as well as damage to the ecosystems of streams and other waterways, special precautions should be taken. A specially designed separation tank can pull the DE and other solids from the water before it is discharged. Otherwise, consult local regulations for the proper disposal of DE waste water.