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Thread: First time SWG - Pool School pH versus manufacturer pH

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    First time SWG - Pool School pH versus manufacturer pH

    My wife and I have been keeping a small 18' for several years now using an old pool frog tri-chlor feeder without any minerals. It has worked well for us with a few exceptions: 1) when I increase filter run time I don't always remember to adjust the feeder and the chlorine spikes 2) I lose track/forget to check it for replacement and my chlorine level crashes 3) we have very little refill need and the tri-chlor drives the CYA up. I realize that except for the last item, all of these are my shortcomings. However it occured to me that all of them could be addressed by an SWG.

    I'm getting ready to balance the water and found the SWG manufacturer recommendations agree right down the line with the Pool School's (http://www.troublefreepool.com/pool-...ater_generator) except for pH. The manufacturer calls for 7.0 to 7.4 while Pool School calls for 7.5-7.6. I should also mention I plan to go with borates...

    I like the higher values as they match my fill water. What are the reasons/implications for using the higher pH range for SWG performance, Cell longevity, Maintenance of the SWG? Just as or perhaps more importantly, what are the implications for getting and keeping my pool trouble free?
    ____________________________________________________________ ________
    George (7500 gal AG, sand filter, way too busy not to have a Trouble Free Pool)

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    duraleigh's Avatar
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    Re: First time SWG - Pool School pH versus manufacturer pH

    Not that big of a deal either way. Acceptable range for pool water is generally 7.0 - 7.8 so most folks think about 7.4 is a sweet spot. If you keep your pH anywhere in the 7's, you will have no issues.

    Now, after saying that SWG pools have a tendency towards rising pH so to keep from having to bring it down every couple of days, I wouldn't keep it at 7.8

    I would start it at 7.2, let it rise to 7.8 and bring it to 7.2 again. Others prefer more precise control and try to maintain 7.4 pretty constant......that's OK, too.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

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    JasonLion's Avatar
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    Re: First time SWG - Pool School pH versus manufacturer pH

    The PH will be more stable if you don't lower it as much. Low PH tends to cause CO2 outgassing, which raises the PH, and you end up adding more acid, which lowers TA, and so on. If you keep PH a little higher, around 7.6 or 7.8, things tend to stabilize and you can stop adding acid. The counter point is that high PH increases the risk of calcium scaling. Still, if you follow our recommended levels there won't be any calcium scaling, as we have adjusted the other levels to prevent that problem.
    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

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    Re: First time SWG - Pool School pH versus manufacturer pH

    Given what Jason is saying about higher pH contributing to calcium scaling I am sure they are looking out for the salt cell. My CH is only 80 ppm. Since I don't have to worry about CH with a vinyl liner I can take advantage of that to offset any pH contribution to calcification of the cell.

    This is all looks pretty promising for overcoming some of my shortcomings... If it does my wife will be thrilled. She doesn't like when my shortcomings affect her swim...


    Thanks for taking the time to share your insights. I'll come back later and let you know how it turns out...
    ____________________________________________________________ ________
    George (7500 gal AG, sand filter, way too busy not to have a Trouble Free Pool)

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    Re: First time SWG - Pool School pH versus manufacturer pH

    Quote Originally Posted by RebelRidin
    1) when I increase filter run time I don't always remember to adjust the feeder and the chlorine spikes ... However it occured to me that all of them could be addressed by an SWG.
    With a SWG, you'll still need to remember to adjust the % output if you increase or decrease pump run time.
    25' x 13' Roman, 12000 gal IGP, Plaster, with 500 gal Spa
    SWG, 1 HP Max Flo Pump, C-900 cartridge filter
    Solar heat

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    Re: First time SWG - Pool School pH versus manufacturer pH

    Quote Originally Posted by lborne

    With a SWG, you'll still need to remember to adjust the % output if you increase or decrease pump run time.

    Hi lborne,

    I should have mentioned that I decided to go with a Chlorease unit. I realize it is on the low end of things and doesn't have a self cleaning cell but the hang on the wall design with its own timer addressed having various pump runs without impacting chlorine output. I do plan to time it to run during the regular filter run to circulate the chlorine. We run the filter at least 8 hrs/day and I don't expect to need the generator more than 6 hours/day.... at least that's the plan.

    Hopefully it works out as I just finished balancing the water, adding the borates and installing the generator yesterday morning.
    ____________________________________________________________ ________
    George (7500 gal AG, sand filter, way too busy not to have a Trouble Free Pool)

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