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Thread: How long should I backwash for

  1. Back To Top    #1
    hawkeye's Avatar
    Join Date
    Jun 2009

    How long should I backwash for

    I usually do it for about a minute or so this long enough to flush out sand? I'm running a 22 inch sand filter with 150 lbs sand......thanks and nice to be back on boards it has been awhile hello all!

    18ft 52in deep doughboy 8000 gallons
    22 in sand filter
    1 1/2 pump
    tk-2006 test kit that rocks!
    12.5% chlorine
    aqua critter vac

  2. Back To Top    #2

    Re: How long should I backwash for

    You should backwash until the water going through the sight glass is basically clear.
    16x32 Oval In-ground Vinyl, ~17,000 gallons, Hayward 1hp Superpump, Hayward S245T Sand Filter

    Worn out sand? sand-filter-expert-help-t30049.html
    Drain the easy way: cyanuric-acid-blues-draining-pool-t43843.html , pool-school/chlorine_cya_chart_shock , pool-school/shocking_your_pool

  3. Back To Top    #3
    linen's Avatar
    Join Date
    Jul 2010
    Twin Cities, MN

    Re: How long should I backwash for

    what macgully said

    Sometimes the backwash starts out clear, then becomes cloudy/opaque before becoming clear again. I would guess my average flush is around 1.5 minutes maybe a little less. Don't forget to got to rinse and let the valve clear (you use the sight glass for this too), before going back to filter.

    Also, don't flush until your "clean pressure" goes up 25%...sand filters are actually become a little better at filtering as they get dirty.
    TFP Expert who uses Pool School and my TF100 test kit along with PoolMath for my: Round 11K gallon AGP with deep end, 20" sand filter, Matrix 1hp 2spd, 6 2ftX20ft solar panels (and solar cover!), Intex SWCG (copper bars disconnected) and a Rubadub hot tub (chlorine). The SLAM process is not finished until: 1. CC < 0.5 ppm, 2. An OCLT < 1.0 ppm and, 3. The water is crystal clear.

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