Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 7 of 7

Thread: CYA and Chlorine

  1. Back To Top    #1
    spoonman's Avatar
    Join Date
    Jun 2016
    Location
    Peoria, AZ
    Posts
    249

    CYA and Chlorine

    Hi. I'm looking for an answer on testing chlorine relative to CYA.

    Do the free chlorine tests compensate for the amount of CYA in the water? I understand there is a CYA/chlorine chart showing the required amount of chlorine at various CYA concentrations. However, most OTO test kits show an ideal chlorine range of around 1.5-2ppm. Why is this? If I run CYA at around 50 or 60, the ideal chlorine ppm would be off the chart if the OTO test doesn't compensate for CYA.
    14x28 IG Rounded Rectangle, 6" aqua tile, White plaster, Gray Acrylic deck, 4' Baja Step (18"), aerator jets, 3-step InterFab SS Ladder, Pentair Intelliflo VS Pump, Pentair TR100C Sand Filter, Stenner Econ E10T2A (chlorine), K-2006, Zodiac Baracuda G3 pool cleaner

  2. Back To Top    #2
    Mod Squad jblizzle's Avatar
    Join Date
    May 2010
    Location
    Tucson, AZ
    Posts
    40,855

    Re: CYA and Chlorine

    There is no compensation in the tests. And that is why we recommend the FAS-DPD chlorine test as it can much more accurately test higher FC levels which are needed when CYA is in the water.
    Jason, TFP Moderator
    18k IG pebblesheen pool, Hayward ProLogic P4 w/ T-15 SWG, Pentair 1HP 2-speed Superflo, Hayward 6020 DE filter
    500 sqft Heliocol solar panels, ThePoolCleaner, TF-100 test kit w/ SpeedStir
    Pool School + Test Kit + PoolMath = A TROUBLE FREE POOL
    If you found TFP helpful and we saved you money ... Become a TFP Supporter!

  3. Back To Top    #3

    TFP Guide

    Jezza's Avatar
    Join Date
    Jan 2015
    Location
    Bunbury, WA, Australia
    Posts
    948

    Re: CYA and Chlorine

    The manufacturers of testing equipment also don't generally factor in the FC/CYA ratio, which obviously requires higher levels of FC for the recommended CYA levels.
    11 000 gallons, IG, Fibreglass, Monarch Sand Filter, Davey Typhoon C100M 1HP pump, Davey Chloromatic Mc16CTO ESR SWG, Davey Pool Wall Climba Robot, Daisy Solar Cover,
    K-2006

  4. Back To Top    #4

    In the Industry

    Donldson's Avatar
    Join Date
    Jun 2009
    Location
    NW Ohio
    Posts
    3,212

    Re: CYA and Chlorine

    Quote Originally Posted by spoonman View Post
    If I run CYA at around 50 or 60, the ideal chlorine ppm would be off the chart if the OTO test doesn't compensate for CYA.
    You know what I say when someone tells me something is "off the chart?"

    "You need a better chart." FAS-DPD.
    JD - 28' Round Above Ground Pool, 17,000 Gallons. Dual speed Jacuzzi pump with cartridge filter. Dual speed 1 HP pump, Hayward S210T sand filter
    Pool School - PoolMath

  5. Back To Top    #5


    TFP Guide

    domct203's Avatar
    Join Date
    Jun 2015
    Location
    CT
    Posts
    3,892

    Re: CYA and Chlorine

    Quote Originally Posted by spoonman View Post
    Hi. I'm looking for an answer on testing chlorine relative to CYA.

    Do the free chlorine tests compensate for the amount of CYA in the water? I understand there is a CYA/chlorine chart showing the required amount of chlorine at various CYA concentrations. However, most OTO test kits show an ideal chlorine range of around 1.5-2ppm. Why is this? If I run CYA at around 50 or 60, the ideal chlorine ppm would be off the chart if the OTO test doesn't compensate for CYA.
    This is exactly why we recommend using a FAS/DPD chlorine test, and mention that the OTO is really only good for confirming the presence of chlorine, not the actual amount with any accuracy.
    Dom - TFP Guide
    Intex 18' X 48" Ultra Frame AGP 6700 gallons | Two Intex CS8110 SWG's | Hayward Pro Series 21" Sandfilter | Hayward 1.5HP Power Flo Matrix pump | Hayward Thru-wall Skimmer | Wanda the Whale | 72 sq ft of Sungrabber Solar Panels with Hayward GLC-2P-A | Taylor K2006 Test Kit, Sample Sizer & Speed Stir | Click Here To Become a TFP Supporter!

  6. Back To Top    #6
    spoonman's Avatar
    Join Date
    Jun 2016
    Location
    Peoria, AZ
    Posts
    249

    Re: CYA and Chlorine

    Guess it's time to get a FAS/DPD. Thanks for the help guys and gals.
    14x28 IG Rounded Rectangle, 6" aqua tile, White plaster, Gray Acrylic deck, 4' Baja Step (18"), aerator jets, 3-step InterFab SS Ladder, Pentair Intelliflo VS Pump, Pentair TR100C Sand Filter, Stenner Econ E10T2A (chlorine), K-2006, Zodiac Baracuda G3 pool cleaner

  7. Back To Top    #7
    Divin Dave's Avatar
    Join Date
    Oct 2013
    Location
    Longview, Texas
    Posts
    5,125

    Re: CYA and Chlorine

    The pool industry in general doesn't recognize the FC/CYA relationship and that's why you see their FC recommendations of between 1 and 3.

    Even though the effectiveness of the method, (backed up by solid science) of keeping a pool completely free of pathogens as well as algae, has been known since 1973, they have no interest in promoting the FC/CYA ratio that TFP does.

    If they did recognize and promote it, then no one would need to buy all of the expensive chemicals which the pool stores and chemical makers sells.

    The Pool Industry consists of businesses which exist to make as much money as they can. Providing the pool owner products that work for the long term is not in their best interest. They need you to repeatedly purchase their expensive products so they can stay in business. Whether or not whatever they can sell you is what you really need doesn't seem to be of any consequence to them.

    It's pretty much as simple as that.


    Quote Originally Posted by spoonman View Post
    Hi. I'm looking for an answer on testing chlorine relative to CYA.

    Do the free chlorine tests compensate for the amount of CYA in the water? I understand there is a CYA/chlorine chart showing the required amount of chlorine at various CYA concentrations. However, most OTO test kits show an ideal chlorine range of around 1.5-2ppm. Why is this? If I run CYA at around 50 or 60, the ideal chlorine ppm would be off the chart if the OTO test doesn't compensate for CYA.
    Divin Dave,
    IG Vinyl, 15' x 30', 3 1/2' - 6' deep, Oval, ~15K gal, Intelliclor IC40, Intelliflo VS pump, Clean and Clear 420 Filter, auto-fill-disabled, Retrofit LED Color Light, Dolphin Nautilus Robot, TF100 Test Kit, Taylor K1766 Salt Test Kit, Tftestkit Pressure Gauge.
    www.tftestkits.net Experience- it's what's learned just after you needed it most !!

Posting Permissions

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