Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 12 of 12

Thread: dilute water for pH test with FC 10+

  1. Back To Top    #1
    tedinelkgrove's Avatar
    Join Date
    Jul 2009
    Location
    Elk Grove, CA
    Posts
    98

    dilute water for pH test with FC 10+

    I thought I read somewhere about diluting water sample to get a more accurate pH reading when FC is 10+? Is this possible? Since my minum FC is always 10+, I am never really able to get an accurate pH reading. Should I let it drop below 10 once in a while?

    I know I need to drain pool to lower CYA, which would also take care of this issue as well.
    ~15000 gallon inground, plaster pool
    Jandy CL460 Cartridge Filter Tank, Jandy Stealth SHPF 1.5hp pump, Pentair Legend II cleaner
    Leslie's DPD Complete Test Kit, TF Tests FAS-DPD Chlorine Test Kit
    Heliocol solar pool heating (HC-40 x6)

  2. Back To Top    #2
    Guest

    Re: dilute water for pH test with FC 10+

    Quote Originally Posted by tedinelkgrove
    I thought I read somewhere about diluting water sample to get a more accurate pH reading when FC is 10+? Is this possible?
    In a word, no.
    Quote Originally Posted by tedinelkgrove
    I know I need to drain pool to lower CYA, which would also take care of this issue as well.
    Bingo!

  3. Back To Top    #3
    tedinelkgrove's Avatar
    Join Date
    Jul 2009
    Location
    Elk Grove, CA
    Posts
    98

    Re: dilute water for pH test with FC 10+

    are pH meters more reliable when FC is 10+?
    ~15000 gallon inground, plaster pool
    Jandy CL460 Cartridge Filter Tank, Jandy Stealth SHPF 1.5hp pump, Pentair Legend II cleaner
    Leslie's DPD Complete Test Kit, TF Tests FAS-DPD Chlorine Test Kit
    Heliocol solar pool heating (HC-40 x6)

  4. Back To Top    #4

    Join Date
    Mar 2007
    Location
    San Rafael, CA USA
    Posts
    12,082

    Re: dilute water for pH test with FC 10+

    Assuming the meter is a good one and recently calibrated, then the answer is yes.
    16,000 gallon outdoor in-ground 16'x32' plaster pool; Pentair Intelliflo VF pump; Pentair IntelliTouch i9+3s control system; Jandy CL-340 square foot cartridge filter
    12 Fafco solar panels; Purex Triton PowerMax 250 natural gas heater (200,000 BTU/hr output); automatic electric pool safety cover; 4-wheel pressure-side "The Pool Cleaner"

  5. Back To Top    #5

    In the Industry

    duraleigh's Avatar
    Join Date
    Apr 2007
    Location
    Sebring, Florida
    Posts
    30,077

    Re: dilute water for pH test with FC 10+

    One of the things you will see quoted frequently on the forum is that pools with very high CYA can be dealt with but it is seldom worth the hassle. Yours is a good example.

    Chem geek's response may lead you to some encouragement but let me damper that a little bit... Meters are not only expensive but their need for calibration is not a one time thing. Very, very few residential pool owners deal with them.

    Eventually, a reduction in CYA will make your pool far more user-friendly in many, many respects.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  6. Back To Top    #6
    tedinelkgrove's Avatar
    Join Date
    Jul 2009
    Location
    Elk Grove, CA
    Posts
    98

    Re: dilute water for pH test with FC 10+

    Agreed. It's time to bite the bullet, again, and drain some water.
    ~15000 gallon inground, plaster pool
    Jandy CL460 Cartridge Filter Tank, Jandy Stealth SHPF 1.5hp pump, Pentair Legend II cleaner
    Leslie's DPD Complete Test Kit, TF Tests FAS-DPD Chlorine Test Kit
    Heliocol solar pool heating (HC-40 x6)

  7. Back To Top    #7
    Guest

    Re: dilute water for pH test with FC 10+

    Quote Originally Posted by tedinelkgrove
    Agreed. It's time to bite the bullet, again, and drain some water.
    considering the cost of a GOOD pH meter (you are looking at a few hundered to say the least--remember I said a GOOD meter), the cost of standard solutions for calibrating the meter, the cost of replacement electrodes (they are delicate, need to be stored properly or they become useless, they break, and wear out), and the time involved to keep the meter calibrated you have made a wise decision.

  8. Back To Top    #8
    tedinelkgrove's Avatar
    Join Date
    Jul 2009
    Location
    Elk Grove, CA
    Posts
    98

    Re: dilute water for pH test with FC 10+

    I am getting an early start tomorrow and heading out to rent the submersible pump. I am going to have the garden hose adding water as I pump out. I know the flow rate of the pump is greater than my hose, but I figure draining half the pool and adding fresh simultaneously will hopefully bring my CYA from 150 to 30-50ppm in one drain.

    When I get the pool filled back up, what chemical levels do I want to address first, pH, FC/CC, CH, TA, etc?

    Thanks.
    ~15000 gallon inground, plaster pool
    Jandy CL460 Cartridge Filter Tank, Jandy Stealth SHPF 1.5hp pump, Pentair Legend II cleaner
    Leslie's DPD Complete Test Kit, TF Tests FAS-DPD Chlorine Test Kit
    Heliocol solar pool heating (HC-40 x6)

  9. Back To Top    #9

    In the Industry

    duraleigh's Avatar
    Join Date
    Apr 2007
    Location
    Sebring, Florida
    Posts
    30,077

    Re: dilute water for pH test with FC 10+

    what chemical levels do I want to address first, pH, FC/CC, CH, TA, etc?
    Adjust your pH first. Then get your FC at the correct levels (or start the shock process) CH and TA can be considered fine tuning and your CYA should be very close to correct.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  10. Back To Top    #10
    tedinelkgrove's Avatar
    Join Date
    Jul 2009
    Location
    Elk Grove, CA
    Posts
    98

    Re: dilute water for pH test with FC 10+

    Thanks for the replies. I am currently on second drain this weekend. The first brought CYA down to 70ppm. One more and my CYA nightmares are over. Hopefully I won't have to drain the pool again for years. Its not the work, its my wife about not being able to use the pool when it is 100+F today.
    ~15000 gallon inground, plaster pool
    Jandy CL460 Cartridge Filter Tank, Jandy Stealth SHPF 1.5hp pump, Pentair Legend II cleaner
    Leslie's DPD Complete Test Kit, TF Tests FAS-DPD Chlorine Test Kit
    Heliocol solar pool heating (HC-40 x6)

  11. Back To Top    #11
    tedinelkgrove's Avatar
    Join Date
    Jul 2009
    Location
    Elk Grove, CA
    Posts
    98

    Re: dilute water for pH test with FC 10+

    After a long weekend draining and filling, the numbers are in:

    CYA ~25ppm
    TA ~110ppm
    CH ~80ppm

    pH 7.8
    FC 4.5

    For the CYA, i threw a trichlor puck in the pool. For CH I was going to Leslies to get some calcium increaser. Any other ideas?
    I added HCl to bring pH down to 7.5.
    ~15000 gallon inground, plaster pool
    Jandy CL460 Cartridge Filter Tank, Jandy Stealth SHPF 1.5hp pump, Pentair Legend II cleaner
    Leslie's DPD Complete Test Kit, TF Tests FAS-DPD Chlorine Test Kit
    Heliocol solar pool heating (HC-40 x6)

  12. Back To Top    #12
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: dilute water for pH test with FC 10+

    Raise CYA just a little and CH quite a bit and you should be fine.
    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

Posting Permissions

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