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Thread: Better Test for CYA?

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    Join Date
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    Better Test for CYA?

    BBB working great so far after Spring Baquacil conversion but I am a little concerned about getting accurate CYA readings. The test is so critical to proper treatment yet it is so subjective. Today I did my normal Saturday am readings and got an initial result of between 50-60. Last week I was at 40, which was exactly what I have been running. No added CYA and only a little evaporation so I was concerned with the big jump. I rinsed, resampled and re-tested, this time being very careful to hold the cylinder exactly waste level and in proper daylight. Result = 40 ppm. I am 5'6" tall with relatively poor vision (yes, I had my glasses on!). If I were 6'5" with eagle eyes, I expect that I might get a different reading. I will order the 50 ppm standard solution to "calibrate" my eyes.

    My question: Is there a sophisticated lab test (e.g., turbidity meter, nephlometer, etc) to accurately measure CYA? If so, what is the relationship between the reading and CYA level?

    What do the pool stores use and which national outlet actually does this test? I realize it is difficult to trust the "kids" running the tests in the stores, but if I knew the technology I might be able to access it at one of the labs where I work. (And besides, I am just curious - This is Chemistry 201, right?).

    In the interest of complete disclosure my morning readings are:

    FC 4.5
    CC 0
    pH 7.6
    TA 90
    CYA 40
    CH 70
    phil_d
    20,000 gal. vinyl liner pool
    Hayward Perflex EC-65 DE filter w/1.5 hp Hayward Super Pump
    Liquidator w/ 3/8" upgrade
    Aquabot Jr. pool cleaner

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    JasonLion's Avatar
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    Re: Better Test for CYA?

    There is a several hundred dollar specialty tester that is better than the usual CYA test at low levels, about the same at more reasonable levels. Other than that, the standard test is the best you are going to get. Pool stores are routinely way way off on the CYA test.

    You can learn to do the test reliably with practice.
    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: Better Test for CYA?

    If anyone knows what the test principle of the specialty tester is I would be interested. As I said, I have access to some sophisticated labs, but mostly I'm just interested. A web link might be helpful.
    phil_d
    20,000 gal. vinyl liner pool
    Hayward Perflex EC-65 DE filter w/1.5 hp Hayward Super Pump
    Liquidator w/ 3/8" upgrade
    Aquabot Jr. pool cleaner

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    Re: Better Test for CYA?

    We test CYA with a photometer and it seems to give pretty good readings - we were concerned about our testing procedure so got some had different people to carry out the test. The FC results were pretty variable, but the CYA results were in good agreement. Our kit is the old version of the Lovibond PC Checkit 3 in 1 Cl pH Cys, and I think it measures CYA up to 200. I'm sure there must be equivalent kit in the US.
    90k litres, outdoor in ground pool, concrete, painted (I hate paint)
    Sta-Rite 5P2R 1.5 Hp pump, undersized sand filter (needs upgrading).

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    Re: Better Test for CYA?

    I use a plain old UV spectrophotometer with really good results. I use the method of standard addition.

    http://www.troublefreepool.com/cya-a...uv-t15153.html
    AGP partially buried, with surrounding deck and flower bed. 12 x 24 oval x 48" deep Celebration by Forum. Steel sides, vinyl liner. Hayward 2 HP sand pump. Flower fountain - works well to cool water up to 10 degrees.

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    svenpup's Avatar
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    Re: Better Test for CYA?

    You can get a 50ppm standard solution so you can see what the end point should really look like.

    http://tftestkits.net/R-7065-CYA-Standa ... n-p34.html
    TFP Method Advanced Intermediate
    • 17,500 gallons - In Ground - Plaster - Hayward Swimclear 3020 Cartridge Filter - Sta-Rite Max-E-Glas Main Pump upgraded with A.O. Smith B2980 E-Plus New Centurion Two-Speed Motor - Polaris 280 Cleaner with Polaris PB4-60 Booster Pump - TightWatt2 Timer - Taylor K-2006 Test Kit - Pool Pilot Digital Nano SWCG

    Helpful Links: Pool School, BBB for Beginners, How to Shock (hint...it's a process not a product), Chlorine/CYA Chart, Jason's Pool Calculator

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    another one's Avatar
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    Re: Better Test for CYA?

    You can get a 50ppm standard solution so you can see what the end point should really look like.
    Can you dillute the standard solution with 50% distilled water to measure 25? I'm trying to get my CYA down to 20 to 25 and my readings are bouncing rather than lowering as I slowly replace water - but I'm also raising the temperature of my pool from 64 (last week) to 80 (today). I warmed up the cooler samples by placing it in a bowl of hot water to get it above 70 degrees.
    29,000 gallon, 18' x 44' Indoor plaster pool - 8'x'8 spa in corner. Well water, TF-100,
    pool cover, Pentair MasterTemp 400k btu heater, Jandy RS-4, 4 x 105 sq ft cartridge filters,
    Wisperflow WFE-4 1.0 HP pump for pool, WFE-6 1.5 HP pump for spa jets, MagnaSweep.

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    Re: Better Test for CYA?

    Quote Originally Posted by another one
    Can you dillute the standard solution with 50% distilled water to measure 25?
    Yes, you can.
    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"

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    svenpup's Avatar
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    Re: Better Test for CYA?

    Why are you shooting for 20?
    TFP Method Advanced Intermediate
    • 17,500 gallons - In Ground - Plaster - Hayward Swimclear 3020 Cartridge Filter - Sta-Rite Max-E-Glas Main Pump upgraded with A.O. Smith B2980 E-Plus New Centurion Two-Speed Motor - Polaris 280 Cleaner with Polaris PB4-60 Booster Pump - TightWatt2 Timer - Taylor K-2006 Test Kit - Pool Pilot Digital Nano SWCG

    Helpful Links: Pool School, BBB for Beginners, How to Shock (hint...it's a process not a product), Chlorine/CYA Chart, Jason's Pool Calculator

  10. Back To Top    #10
    another one's Avatar
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    Re: Better Test for CYA?

    Why are you shooting for 20?
    Indoor pool so no real sun on the water, just filtered sunlight.
    29,000 gallon, 18' x 44' Indoor plaster pool - 8'x'8 spa in corner. Well water, TF-100,
    pool cover, Pentair MasterTemp 400k btu heater, Jandy RS-4, 4 x 105 sq ft cartridge filters,
    Wisperflow WFE-4 1.0 HP pump for pool, WFE-6 1.5 HP pump for spa jets, MagnaSweep.

  11. Back To Top    #11
    svenpup's Avatar
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    Re: Better Test for CYA?

    Got it...just making sure
    TFP Method Advanced Intermediate
    • 17,500 gallons - In Ground - Plaster - Hayward Swimclear 3020 Cartridge Filter - Sta-Rite Max-E-Glas Main Pump upgraded with A.O. Smith B2980 E-Plus New Centurion Two-Speed Motor - Polaris 280 Cleaner with Polaris PB4-60 Booster Pump - TightWatt2 Timer - Taylor K-2006 Test Kit - Pool Pilot Digital Nano SWCG

    Helpful Links: Pool School, BBB for Beginners, How to Shock (hint...it's a process not a product), Chlorine/CYA Chart, Jason's Pool Calculator

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