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Thread: when i test ph pool -it reads 7.4 thenif i let it sit it goe

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    when i test ph pool -it reads 7.4 thenif i let it sit it goe

    when i test ph pool -it reads 7.4 thenif i let it sit it goes to 8.0 -- using taylor k-2006 -
    38000 gal inground - 1.5 hp hayward superpump 300lb sandfilter-k-2006 test kit-diving board-slide-10' x 15' tiki bar-outdoor living room

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    duraleigh's Avatar
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    Re: when i test ph pool -it reads 7.4 thenif i let it sit it

    Use the 7.4 result. The pH test is essentially immediate and disregard anything that it may do later.
    Dave S.
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    harleysilo's Avatar
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    Re: when i test ph pool -it reads 7.4 thenif i let it sit it

    Quote Originally Posted by duraleigh
    Use the 7.4 result. The pH test is essentially immediate and disregard anything that it may do later.
    So I got into fish keeping over the winter....actually my kids wanted a fish tank. So now i got a fancy test kit for our fish tank and one for the pool. I remember reading threads last year where people who were big into fish keeping did different tests on their pools and commented about it but i've forgotten the specifics. However, the forum for fish i read suggests a true PH test requires letting the water sit, preferably aerated for a day before testing. But that is for testing Tap water that may contain CO2. I would assume a pool, open to the air, would not have CO2 in the water, but hey what do i know. So what is the explanation for the different readings? OR is the OP just leaving the test water with drops in it and noticing that after a hour the color has changed more? Or is OP re-testing with water that has been out of the pool for awhile?
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    JasonLion's Avatar
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    Re: when i test ph pool -it reads 7.4 thenif i let it sit it

    Pool water is highly carbonated (lots of CO2). In the pool it is difficult for the CO2 to outgas, as there is comparatively very little surface compared to the volume of water. In a small container the surface to volume ratio is far higher and it will outgas rapidly. There are also other reactions that will change the PH, such as the breakdown of chlorine, which will progress far more quickly in a small container than it does in your pool. Essentially, the small container drifts rapidly while the pool is comparatively stable. If you want to know what is happening in the pool, you need to do the test reasonably promptly.
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    harleysilo's Avatar
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    Re: when i test ph pool -it reads 7.4 thenif i let it sit it

    Thanks Jason!
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