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Thread: Percentage of DE after backwash??

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    Percentage of DE after backwash??

    Hi All,
    I'm just going to backwash my filter unitl I can do a through cleaning for the end of the season in about a month. My unit calls for 4.8lbs of DE but I recall if backwashing it should be less. I thought it was 80%. Can anyone confirm?
    15,500 gal, inground gunite pool with 7 ft spa, 2 speed pump 2hp/.33hp, 3/4 hp booster pump, Intermatic P1353 timer, AutoPilot SC-48, Sand filter with ZeoBest, Heater, that I never use . . .

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    Join Date
    Mar 2007
    Coastalish 'down easter'

    Re: Percentage of DE after backwash??

    Joe, as long as you wait until the filter's pressure gauge is ~ 8 - 10 psi higher than clean before you do a thorough backwash (multiple 'backwash/ rinse' cycles until the backwash water comes out ~ clean), you'll only get ~ 80% of the DE out, so only add ~ 3.75 - 4 lbs. If you backwash when the pressure only rises 2 -3 lbs, add the full amount 8)

    Here is the 'use and care for de filters' post for you or anyone else who needs it.

    Hope all goes well and you can get some more good use out of the pool before you close it and really clean the filter
    Luv& Luk

    Having done construction and service for 4 pool companies in 4 states starting in 1988, what I know about pools could fill a couple of books - what I don't know could fill a couple of libraries :-D

    POOL SCHOOL, TF Testkits, Jason's Pool Calculator, CYA vs. cl chart, (Just a few DARNED handy links!)

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