Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 6 of 6

Thread: Filter pressure a direct relationship to filtration time?

  1. Back To Top    #1

    Join Date
    Mar 2009
    Location
    Charlotte, NC
    Posts
    530

    Filter pressure a direct relationship to filtration time?

    SAND Filter pressure a direct relationship to SAND filtration time?

    If when I turn my cleaner on, and the SAND filter pressure drops 50%, is it correct to assume that the amount of SAND filtration is reduced by 50%, and so to achieve the same amount of SAND filtration, I need to increase the pump Run-Time by 50% ( to achieve the ideal daily “SAND filter/turnover” time)?

    Thanks
    19,800 gallons (closed/winter 18,654 gal); plaster; 18x34 Ft kidney bean shape, Depth 3Ft-5Ft. Built 1992
    Pentair Whisper Flow Pump 1HP. Winter safety cover w anchors.
    Sand filter, Pentair Sand Dollar Top Mount Model SD80; Effective Filtration Area 3.5SF
    - FlowRate 75GPM, 8Hr 36,000, 10Hr 45,000, 12Hr 54,000; Pressure Weight 50PSI
    BBB (Hayward Chlorinator when leave town). Polaris 360 cleaner.

  2. Back To Top    #2
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Filter pressure a direct relationship to filtration time

    No, there isn't any direct relationship like that one. That is a reasonable rough guess, but the actual relationship is far more complex and could be very different than that. The best way to determine the best filter run time is empirically, ie try it and see what happens. My guess is that you won't need to increase the pump run time by nearly that much, but the only way to know is to try it.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  3. Back To Top    #3
    Mod Squad Bama Rambler's Avatar
    Join Date
    Jun 2009
    Location
    SouthWest Alabama
    Posts
    22,347

    Re: Filter pressure a direct relationship to filtration time

    [edit] I wasn't thinking about the pressure for the cleaner branching off before the filter. Back to your regularily scheduled program

    [s:1bp0wixc]You're attaching a pressure side cleaner and your filter pressure drops? Unless you normally have one very small eyeball your pressure should actually go up.[/s:1bp0wixc]

    Regardless, Jason already answered your question.
    Dave J. TFP Moderator
    24' x 52" Round AGP. 2hp/hp SPL Power-Flo 2-speed pump. 200sqft Waterway Cartridge Filter. 45MHP2(3GPD) Stenner Peristaltic Pump
    Pool School ----- Pool Math ----- TF-Test Kit

  4. Back To Top    #4

    Join Date
    Mar 2009
    Location
    Charlotte, NC
    Posts
    530

    Re: Filter pressure a direct relationship to filtration time

    Thanks guys. FWIW, my cleaner bypasses the sand filter & has its own plastic jar with a filter in it (& its own pressure gauge), so the qty of water going into the SAND filter is less and that drops the pressure in the SAND filter.

    Am I correct that the “quality” of filtration by my cleaner’s filter is inferior to that of my SAND filter? If I’m wrong or just splitting hairs, then I won't need to alter the pump RunTime at all, or as Jason implied, certainly not add 50% to the RunTime.

    I edited my original post to read more clearly.
    19,800 gallons (closed/winter 18,654 gal); plaster; 18x34 Ft kidney bean shape, Depth 3Ft-5Ft. Built 1992
    Pentair Whisper Flow Pump 1HP. Winter safety cover w anchors.
    Sand filter, Pentair Sand Dollar Top Mount Model SD80; Effective Filtration Area 3.5SF
    - FlowRate 75GPM, 8Hr 36,000, 10Hr 45,000, 12Hr 54,000; Pressure Weight 50PSI
    BBB (Hayward Chlorinator when leave town). Polaris 360 cleaner.

  5. Back To Top    #5
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Filter pressure a direct relationship to filtration time

    The small jar filter on that kind of pressure side cleaner is no where near as good as the sand filter. It is designed to catch things large enough that they won't get through the drive vanes of the cleaner, which is a much larger size than what a sand filter catches.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  6. Back To Top    #6

    Join Date
    Mar 2009
    Location
    Charlotte, NC
    Posts
    530

    Re: Filter pressure a direct relationship to filtration time

    I edited my original post to read more clearly for BAMA.

    Thanks once again. Last question, promise.
    The ideal “at least one Turnover per day” means one Turnover through my sand filter, right? (I realize there are other reasons for one Turnover per day, but for this discussion)
    19,800 gallons (closed/winter 18,654 gal); plaster; 18x34 Ft kidney bean shape, Depth 3Ft-5Ft. Built 1992
    Pentair Whisper Flow Pump 1HP. Winter safety cover w anchors.
    Sand filter, Pentair Sand Dollar Top Mount Model SD80; Effective Filtration Area 3.5SF
    - FlowRate 75GPM, 8Hr 36,000, 10Hr 45,000, 12Hr 54,000; Pressure Weight 50PSI
    BBB (Hayward Chlorinator when leave town). Polaris 360 cleaner.

Posting Permissions

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