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Thread: pH of 16.9??

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    pH of 16.9??

    So I wanted to confirm my ph test, which kept turning pink despite low chlorine levels. The pool store also got 8.2+ (higher than their chart) and did some "acid demand test" and the lady said it gave an "adjusted ph" level of 16.9!

    Just wondering if that is even possible, and does that mean I will need to put in 61 L of muriatic acid to correct this?!?

    Funny thing is the pool was almost clear april 16th, and the ph was 7.4 as per the pool store. Only thing used since was some cal hypo for a few days, and bleach since then. Here is what the store's tests read:

    FC 3
    ph 8.2
    acid demand 19 drops
    adjusted ph 16.9
    TA 80
    CYA 0
    CH 120

    Any suggestions greatly appreciated, Thanks!
    20,000L (5,200 gal) round AG pool, Hayward sand filter, 1.5hp pump, in the Laurentians, Quebec Canada
    Pool gets medium amount of sun, due to the house and surrounding trees.

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    Re: pH of 16.9??

    Oh also, is there a special way to add the muriatic acid..? The bottle says to turn off the pump for 12 hours...
    20,000L (5,200 gal) round AG pool, Hayward sand filter, 1.5hp pump, in the Laurentians, Quebec Canada
    Pool gets medium amount of sun, due to the house and surrounding trees.

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    Re: pH of 16.9??

    Quote Originally Posted by skurys
    Oh also, is there a special way to add the muriatic acid..? The bottle says to turn off the pump for 12 hours...
    maybe if you are trying to acid wash your pool. You want it to mix in so add the acid in front of a return. Here is a link from pool school

    pool-school/recommended_pool_chemicals

    Also regarding pH, 16.9 is suspicious. Typically pH is only reliably measured to 14. if that were the case it would be extremely toxic and would cause severe burns.

    Maybe get a tf100 test kit and measure it yourself.
    17,800 gallon, IG pool, 595 sq feet (17x35x4.5 avg rectangle), Hayward 525 cartridge filter, diamondbrite, 2 hp 2 speed hayward tristar filter, Stenner 45mhp10 automatically chlorinating

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    Join Date
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    Re: pH of 16.9??

    More evidence of kooky pool store advice, unless that was a typo! And as march said, always add acid in front of a return with the pump running.
    20K gal IG plaster pool, Manually chlorinated with 6% bleach, 1.5 HP Sta-Rite Dura-Glas II pump, Pentair FNS Plus 48 DE filter, Polaris 280

  5. Back To Top    #5

    Re: pH of 16.9??

    Yeah she said its not an actual ph 16.9 but adjusted... (tho even she wasn't sure what that means exactly) I just tried with a ph test with chlorine neutralizer and still gives pink, so its something above 8...

    I put in 500ml and I guess I'll see what it reads tomorrow...
    20,000L (5,200 gal) round AG pool, Hayward sand filter, 1.5hp pump, in the Laurentians, Quebec Canada
    Pool gets medium amount of sun, due to the house and surrounding trees.

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    duraleigh's Avatar
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    Re: pH of 16.9??

    The change in pH in your pool is measurable within 30 minutes to an hour. You can test again soon if you like.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

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    Re: pH of 16.9??

    Not a rocket scientist, but isn't pH by definition 0-14?
    Dave
    Yakima, WA (the Palm Springs of Washington!)
    IG kidney 14k gal, 33 x 18
    vinyl liner
    200 lb Sand filter
    3/4 HP pump
    First time pool owner

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    Isaac-1's Avatar
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    Re: pH of 16.9??

    It must be that new math
    Indoor 20x40 35,000 gallon vinyl pool with 1.5 HP 2 speed Jandy FloPro pump, Hayward EC75 Perflex DE filter, 11 4x12 Techno-Solis solar panels w/ Aquasolar controller, Aquabot Turbo T Robot Cleaner. Also LMI metering chlorine dispenser pump and HotSpring Jetsetter
    I use and endorse TFtestKits TF-100 from http://tftestkits.net
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    Re: pH of 16.9??

    Maybe someone could explain what the acid demand test is in relation to the ph, this is the test she did to come to that value. She added drops until the solution changed and that gave her 16.9
    20,000L (5,200 gal) round AG pool, Hayward sand filter, 1.5hp pump, in the Laurentians, Quebec Canada
    Pool gets medium amount of sun, due to the house and surrounding trees.

  10. Back To Top    #10
    Ohm_Boy's Avatar
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    Re: pH of 16.9??

    I'm sure someone can expound upon that "adjusted" garbage, but we never worry about anything other than actual pH. I think the acid demand test is supposed to give some indicator of how much acid will be needed to reach some arbitrary level, but IMHO it only contributes further points of testing errors and confusion.

    Do yourself a favor - take the "real" pH level, plug it into the PoolCalculator and find out what is needed to reach your target level.
    [center:1kpalu48]Helpful Links: Pool School | CYA/Chlorine Chart | Pool Calculator[/center:1kpalu48]

  11. Back To Top    #11

    Re: pH of 16.9??

    Unfortunately I'm in Canada and don't have the 150$ for the big kits that I can have shipped here.

    But I assumed 8.2 as thats the highest on my ph test, and treated for that, then checked again and added a big more.... now it's starting to come into range yay!
    20,000L (5,200 gal) round AG pool, Hayward sand filter, 1.5hp pump, in the Laurentians, Quebec Canada
    Pool gets medium amount of sun, due to the house and surrounding trees.

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    Ohm_Boy's Avatar
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    Re: pH of 16.9??

    You're on the right track. Shoot for somewhere within 7.2-7.6 on pH.
    [center:1kpalu48]Helpful Links: Pool School | CYA/Chlorine Chart | Pool Calculator[/center:1kpalu48]

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    Re: pH of 16.9??

    Quote Originally Posted by Yakiman
    Not a rocket scientist, but isn't pH by definition 0-14?
    not by definition, it is a log function of the concentration of free hydrogen. Theoretically it can be as high as you want, but practically it is extremely difficult to measure above 14.
    17,800 gallon, IG pool, 595 sq feet (17x35x4.5 avg rectangle), Hayward 525 cartridge filter, diamondbrite, 2 hp 2 speed hayward tristar filter, Stenner 45mhp10 automatically chlorinating

  14. Back To Top    #14

    Re: pH of 16.9??

    Quote Originally Posted by skurys
    Unfortunately I'm in Canada and don't have the 150$ for the big kits that I can have shipped here.

    But I assumed 8.2 as thats the highest on my ph test, and treated for that, then checked again and added a big more.... now it's starting to come into range yay!
    The acid demand test is useful for determining how much acid you need, but the calculation of a pH based on that doesnt sound quite right.

    I like it because apparently my test only goes to 8 (taylor 2006) so the acid demand gives me a better idea of how much acid Im going to need. Am I just barely over 8 or am I waaay over 8.
    17,800 gallon, IG pool, 595 sq feet (17x35x4.5 avg rectangle), Hayward 525 cartridge filter, diamondbrite, 2 hp 2 speed hayward tristar filter, Stenner 45mhp10 automatically chlorinating

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    bobodaclown's Avatar
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    Re: pH of 16.9??

    It depends on the size of the pool. Each drop for the acid demand test is approx 16-17 ounces of 20 baum acid in my pool. For example if my pool ph is 7.8 and it takes 2 drops to lower it to 7.5 for my pool its approx 32 ounces pool caculator comes up with 35. Its in the ball park. Pool calculator is your friend
    17K Kidney Shaped Pool Concrete (Diamond Bright) Pool, 3/4 hp 2 speed 115V Sta-rite Duraglas PEA5D-180L/P2R5D-181L (Impeller C105-92PS Diffuser C1-216P), 1.5 piping, Pentair CC100 Filter , Heat Siphon 100K BTU Heat Pump Pool Heater, Flow meter Blue White Flowmeter Model No. F-30150P, Hayward Astrolight SP0581N, SWCG CalimarTitanium Edition TE45 , Dolphin Nautilus Plus with CleverClean, Lakeland Florida

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