How to backwash a pool filter

If you have a sand filter or a DE filter it needs to be backwashed regularly. A filter backwash is recommended every 2 -6 weeks on average. Backwashing is included in our monthly service cleaning packages.


D.E. is trapped in grids within the filter shell. The D.E. is the filter, not the grids. This is the best type of filter for your pool. When the system is running the D.E. traps all of the debris, dirt, and potential algae. D.E. captures particles as small as 3-5 microns, sand as a comparison captures particles as low as 20 microns.

DE grid

Backwashing means sending water backwards through the filter. This is the process to clean your filter. The backwards flow of water blows all, or most all of the D.E. out of the grids. It is discharged out the discharge pipe. In some instances, the pipe can be buried to send the water away from the filter area.

de discharge

When backwashing, technically, the filter is removed not cleaned. So after backwashing more D.E. must be added back to the grids. This is done by adding the D.E. in the skimmer.

adding DE

The size of the filter determines how much D.E. is needed. Per 10 sq ft of filter area you need 1 pound of D.E.

24 Sq. Ft. 2.4 lbs
36 Sq. Ft. 3.6 lbs
48 Sq. Ft. 4.8 lbs
60 Sq. Ft. 6 lbs
72 Sq. Ft. 7.2 lbs