Filter backwashing is mandatory
If you have a sand filter or a DE filter it needs to be backwashed regularly. A filter backwash is recommended every 4 -8 weeks on average. Backwashing is included in our monthly service cleaning packages.
Backwash of a DE Flter
DE is trapped in grids within the filter shell. The DE is the filter, not the grids. This is the best type of filter for your pool. When the system is running the DE traps all of the debris, dirt, and potential algae. DE captures particles as small as 3-5 microns, sand as a comparison captures particles as low as 20 microns.
This image is the inside of a DE Filter.
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 DE 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.
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.
This scoop size is approximately 1 pound of DE.
The size of the filter determines how much DE is needed. Per 10 sq ft of filter area you need 1 pound of DE But, this chart refers to a filter which is just been cleaned or is brand new. When you backwash a filter you don not remove 100% of the old DE. The rule of thumb is assume you removed about 80% of the DE after doing a backwash.
See below for recommended amounts of DE needed.
36 Square Foot FilterWith a brand new filter or just after a filter cleaning, add back about 3.6 pounds. After a backwash add about 80% or about 2.8 pounds.
Because a backwash alone does not remove all the old DE, a filter cleaning is recommended 1-2 times per year. For our customers, we include 2 free filter cleans per year. See full package details.