Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 7 of 7

Thread: New Pool: DE Filter Pressure vs Backwash frequency

  1. Back To Top    #1
    ssml11's Avatar
    Join Date
    Jul 2014
    Location
    Miami/Florida
    Posts
    131

    New Pool: DE Filter Pressure vs Backwash frequency

    I have a Hayward DE 36 and my new 10k gallon pool was filled exactly one month ago. I haven't done any backwash yet because I was told to backwash only when the filter gauge displays a gain of 10 in pressure.

    The pressure gauge has read 3 since the pool was filled, and it has only gone up maybe a hairline in 30 days.

    I am currently running my ecostar pump at 1300 rpm for 16 hours a day. If I increase the pump's speed to 1800rpm the pressure goes up to 9, so I know the gauge is working.

    The question is, am I ok in not backwashing not even once since pool was filled? At this rate it will take months for gauge to display a gain of 10 in pressure.
    12' X 25' in-ground. Hayward EcoStar Pump, Hayward DE 3620 Filter, Hayward Pro-Logic PS4 with Aqua Connect for automation, Hayward ColorLogic Led lights, Silencer Blower, Four Jandy DeckJets, Salt Pool, Neverlube Valves with One Actuator. Built by owner.

  2. Back To Top    #2

    In the Industry

    duraleigh's Avatar
    Join Date
    Apr 2007
    Location
    Sebring, Florida
    Posts
    30,083

    Re: New Pool: DE Filter Pressure vs Backwash frequency

    Yes, you are ok (sort of). I assume your pool is clear and doesn't get much debris.

    A somewhat better way to test is to test at a higher rpm (enough to get to 10 psi). TFP suggests a backwash at 25% of the clean pressure, so if you now get 10 psi at maybe 1900 rpm, test it at 1900. Then when your psi increases to 12.5 or so (25%) it is time to backwash.

    Most pool gauges are pretty inaccurate especially at low, low pressure so the 10 psi will make it easier to judge your 25% increase.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  3. Back To Top    #3

    Join Date
    Sep 2013
    Location
    Dallas-Ft. Worth Metroplex, TX
    Posts
    810

    Re: New Pool: DE Filter Pressure vs Backwash frequency

    I would use max speed to gauge filter pressure for cleaning purposes.
    14K Freeform Gunite w/60% Blue Quartz plaster, Quad DE filter, Intelliflo VS Pump + Booster for Cleaner, Aquacal Heat Pump

  4. Back To Top    #4
    ssml11's Avatar
    Join Date
    Jul 2014
    Location
    Miami/Florida
    Posts
    131

    Re: New Pool: DE Filter Pressure vs Backwash frequency

    So you guys think I should pump filter speed up for a couple of weeks and see if it goes up?
    Backwashing after 25 percent into? Woao then what's the point of the 10 pressure increase deal?

    And yes, pool water is so clean it looks like zephyrhills water.

  5. Back To Top    #5
    Richard320's Avatar
    Join Date
    Jan 2010
    Location
    San Dimas, CA (LA County)
    Posts
    18,768

    Re: New Pool: DE Filter Pressure vs Backwash frequency

    Quote Originally Posted by ssml11 View Post
    So you guys think I should pump filter speed up for a couple of weeks and see if it goes up?
    Backwashing after 25 percent into? Woao then what's the point of the 10 pressure increase deal?

    And yes, pool water is so clean it looks like zephyrhills water.
    The 10 psi pressure increase is one of those pool store legends like "3 is the ideal chlorine level" without taking CYA into account.

    All you need to do is get a baseline reading at max RPM and then let the thing run at low speed normally. Maybe once a week, take it up to max again and see what the difference is. My DE filter can go months without showing any increase. Once it starts climbing, it tends to climb pretty fast after that.
    16K freeform gunite with spa; Pentair 4000 DE filter; Century Whisperflow 1 HP; Pentair Minimax heater.
    Troublefree does not mean Maintenancefree. It's like brushing your teeth: You can spend a couple minutes a day and pennies a week or go to the dentist once a year and spend several thousand dollars.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

  6. Back To Top    #6

    In the Industry

    Join Date
    Feb 2015
    Location
    San Diego ca
    Posts
    16

    Re: New Pool: DE Filter Pressure vs Backwash frequency

    I backwash open and clean my filters every four months. Then reset it with the correct amount of de

  7. Back To Top    #7
    Patrick_B's Avatar
    Join Date
    Jun 2011
    Location
    Midland TX
    Posts
    15,001

    Re: New Pool: DE Filter Pressure vs Backwash frequency

    Quote Originally Posted by Geelow View Post
    I backwash open and clean my filters every four months. Then reset it with the correct amount of de
    That's great if it works for you, but this can vary greatly from pool to pool.
    TFP Moderator
    Essential Links:
    ABC's Of Pool Chemistry, Test Kits, SLAM Your Pool
    28K Gal IG FreeForm, CLI Quartz, Pentair 36"SF & VS Pump, Dolphin M5, Rheem

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •