How to Backwash your D.E. Filter

IMPORTANT:  These instructions are designed for in ground pools built by Aegean Pools, Inc. and may not work with all pool installations.  These instructions assume you have at least a 6 position multiport valve installed on your filter system that allows you to backwash the filter.  If you do not have this valve this process will not work for you.  Aegean Pools offers no warranty with these instructions.


  1. Turn pump off
  2. Roll out backwash hose (if you have one.)  IMPORTANT NOTE: When you roll the backwash hose out it must be FLAT (not twisted) and NOT kinked.  If you leave a kink in the hose or it is twisted the water WILL blow a hole in the hose.  This is not a warranty issue.
  3. Rotate the Vari-flow valve to the backwash position.
  4. Turn pump on.
  5. Backwash until sight glass is clear.
  6. Turn pump off.
  7. Rotate the Vari-flow valve to Rinse.
  8. Turn pump on.
  9. Run for approximately 20 seconds.
  10. At this point you may repeat the backwash/rinse process up to 2 more times.
  11.  Turn pump off.
  12.   Rotate Vari-flow valve to the filter position.
  13.  Turn pump on.
  14.  Put the amount of D.E. the manufacture calls for less one pound in the skimmer closest to filter. NOTE: It is important that you recharge the filter with D.E. after backwashing the filter or you will damage the internal components of the filter.
  15.  To determine the correct amount of D.E. consult the label on the side of the filter.  Use the amount the manufacture calls for less one pound.  If you have disassembled the filter and cleaned it out then use the full amount the filter requires.
  16.   The process is now complete.  Do not backwash the filter again until the pressure goes up 10 pounds over normal.[1]


Make Model Amount D.E. filter empty Amount of D.E. after backwash
Hayward DE3600/3620

4.5 lbs

3.5 lbs

Hayward DE4800/4820

6 lbs

5 lbs

Hayward DE6000/6020

7.5 lbs

6.5 lbs

Hayward EC40

4 lbs

4 lbs*

Hayward EC65


6 lbs*

Pentair FNS48

4.8 lbs

4.8 lbs

Pentair FNS60

6 lbs

6 lbs

Pentair FNSP48

4.8 lbs

4.8 lbs

Pentair FNSP60

6 lbs

6 lbs

*This is a bump (extended cycle filter) after bumping the filter you do no flush the filter out the D.E. gets used through another cycle.  When flushing is required you should use the bump handle to get as much of the D.E. out as possible.

© Aegean Pools, Inc. 8-27-03


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s