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Thread: Pool & Filter Size Help

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    Pool & Filter Size Help

    I recently purchased and installed a 22in. Hayward Pro Series Sand Pool Filter as replacement for my old 24in filter (specs below). My 22in. sand filter is perfect for my pool as it is only 18K gallons. However, I failed to realize that my pool pump is 1-HP. I was told the most efficient pump for my filter is 3/4 HP. I was wondering if this is going to cause any problems that my pump is too big for my filter, or is this absolutely fine? I have already installed the filter, but if need be, I think I can still return it...but it will be a pain to remove all of the sand, and leaving my pool unfiltered for another week...Anyway feedback would be greatly appreciated!!

    Size: 22in.
    Effective filtration rate: 2.64ft
    Design Flow Rate: 52 GPM
    Turnover: 29,760 gallons in 8 hours
    Sand Required: 250lbs

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    Re: Pool & Filter Size Help

    It's not ideal, but it will work. You could replace your pump impeller with a smaller one to slow down the flow rate.

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    Re: Pool & Filter Size Help

    will there be any noticeable issues? i am deciding if i should return the filter and just order the 24in...and if so, do you know what the quickest way is to remove sand from the filter?

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    Re: Pool & Filter Size Help

    It's not a major problem. You could use the setup as is.

    However, the two main issues are that the filter won't be as effective as it would be with a slower flow rate per square foot of sand surface area and that during backwashing, you could lose some sand due to excessive flow rate.

    A 24-inch sand filter is still too small for that pump. If you are going to get another filter, you should get one rated for about 75 gpm. You could get a cartridge filter instead of sand.

    I think that it would be easiest to just use the filter you have and lower the flow rate by replacing the impeller with a smaller one.

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    Re: Pool & Filter Size Help

    is replacing the impeller something easy to do? would I need to bring it to a pool specialist?

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    Re: Pool & Filter Size Help

    It's not too difficult if you're good at mechanical repairs. Basically, you just remove the bolts to get into the pump, unscrew the old impeller, replace the seal and gaskets and put everything back together.

    You can use what you have without any major problems.

    You can upsize the filter if you feel like it would be better, or you can replace the impeller to slow the flow rate.

    If you want, you can have a service call to have someone replace the impeller for you.

  7. Back To Top    #7

    Join Date
    Oct 2010

    Re: Pool & Filter Size Help

    Hayward recommends the 3/4 hp super pump with the 22" filter (250 lbs of sand) and the 1 hp super pump with the 24" filter (300 lbs of sand).

    The 1 hp will work with the smaller filter, but will use more electricity than the 3/4 hp pump.

    In a few years, when you replace the pump, replace it with a 3/4 hp single speed or a 1 hp/2 speed.


    20x40 free-form IG vinyl, 1hp Hayward superpump, Hayward pro grid DE filter, Raypak heatpump, Goldline Aquarite SWCG, Polaris 280 with booster, and tested using a Taylor K2006.

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    Re: Pool & Filter Size Help

    ahhh, what a mess I am in, I am also considering switching the filter since a bigger filter can turn my pool over quicker and save on electricity...what would be the quickest way to remove sand from a sand filter? is there such thing as too big of a filter? (24in sand filter for a 18k pool too big?)

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    dmanb2b's Avatar
    Join Date
    Apr 2009

    Re: Pool & Filter Size Help

    Nope...the bigger the filter, the better. I have the 22" on a 13k gal pool. A 24" on a 18K gal pool is not too big at all.
    24'x52" AGP (13,500 Gallons), Intex SWG, (2)Solar Bear 4x20 panels, Hayward S220T Filter, 1/2hp Pentair Superflo

    Pool School, TFTestKits, Pool Calculator

  10. Back To Top    #10

    Join Date
    Apr 2011
    Toledo, OH

    Re: Pool & Filter Size Help

    Quote Originally Posted by dmanb2b
    Nope...the bigger the filter, the better. I have the 22" on a 13k gal pool. A 24" on a 18K gal pool is not too big at all.
    I am so new at this that I'm trying to read all I possibly can, boy there is a lot to take in. In reading (and rereading) the Pool School here and similar ones on various other websites I keep running across the figure that a cartridge filter needs a minimun of .25 gpm/ sq' of cartridge. So would that mean that if I wanted to use a 320sq' Pentair clean & clear plus I would need to be running a minimum of 80gpm?

    Sorry if this is bringing up too old a thread.
    The man on top of the mountain didn't fall there.

    24' x 52" Intex ultra frame pool (12,400 gallons) with seperate Intex 2500gph pump and SWG and 2 Intex magnetic pool lights.
    Looking to upgrade to 27-30' semi inground install

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