Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 17 of 17

Thread: CYA Test Accuracy

  1. Back To Top    #1

    Join Date
    Sep 2007
    Location
    Guelph, Ontario, Canada
    Posts
    56

    CYA Test Accuracy

    I have always questioned my ability to measure CYA accurately, and have read the many posts here regarding test accuracy.
    Especially useful was two-cya-kits-consistently-disagree-t37391.html?hilit=cya%20test%20error%20taylor%20cya

    I have a Taylor 2005C kit and I have the CYA view tube that is supposed to make the test a bit easier.
    I get quite repeatable results, but have I have never been convinced the results are accurate.

    In trying to 'calibrate' my results I have used pool stores to compare my measurements.
    Some pool stores match my measurements, but one pool store in particular always measures significantly lower CYA.
    (All other tests are pretty close to my measurements)

    In discussions with them they acknowledged they do not use Taylor test system (I'm pretty certain they use a Lamotte test system since my print out states 'WaterLink DataMate)
    Unfortunately, this is the only store that I actually trust (Its a small independent Mom & Pop shop that have never tried to sell me anything that I didn't already know I needed)

    Last year, as an experiment with the store, I purchased a small vial of Taylor R-0013 from them and asked them to test my water using both systems. They confirmed my result using Taylor, which if I recall was 30ppm higher than their test test results. They could not explain the difference except to say that they are not as experienced with the Taylor method to accurately determine when the dot becomes obscured, and that their experience in real life confirmed their results.

    I have a SWG that requires CYA to be 60-80. This year, my Taylor kit consistently measures 40, while the store testing measured 80. It is not in the stores best interest to measure low as I think I need to by CYA from them and they are saying I don't need it. (they didn't try to sell me anything else)

    Additionally, I have found that my best year for pool maintenance/algae was before I purchased my test kit, and relied solely on this stores CYA test results.

    Is there a fundamental reason why Taylor and Lamotte tests results differ? or is there some other factor why the results would vary?
    Carl Schnurr
    Pool: 96,000 litre, vinyl liner, 1 HP pump, sand filter, Aqua-rite SWG, Hayward e.vac, installed 2005
    Spa: La-Z-Boy 'Relieve', 1300 litre, acrylic, with ozonator, installed 2017

  2. Back To Top    #2
    Mod Squad Bama Rambler's Avatar
    Join Date
    Jun 2009
    Location
    SouthWest Alabama
    Posts
    22,347

    Re: CYA Test Accuracy

    Pool stores are notoriously wrong on cya tests. I've had them show cya in tap water on several occasions. I'd trust your own results.
    Dave J. TFP Moderator
    24' x 52" Round AGP. 2hp/¼hp SPL Power-Flo 2-speed pump. 200sqft Waterway Cartridge Filter. 45MHP2(3GPD) Stenner Peristaltic Pump
    Pool School ----- Pool Math ----- TF-Test Kit

  3. Back To Top    #3
    Mod Squad woodyp's Avatar
    Join Date
    Apr 2010
    Location
    East Texas
    Posts
    9,000

    Re: CYA Test Accuracy

    I gotta try that just for grins Bama! They're usually double what I measure.
    16x32x52" Steel Cornelius Miramar AGP Vinyl liner 13,100 gal. Buried 2 ft.
    2 Speed Hayward Power-Flo Matrix 85 g.p.m. 22" 250lb. sand filter hard plumbed
    Pool Rover Jr., Pool Blaster Max, Diver Dave TF100 Test Kit/Speed Stir
    Margaritaville Frozen Concoction Maker, Liqour Chiller, & Drink Mixer & Party Tub----Collect 'um all!

  4. Back To Top    #4
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: CYA Test Accuracy

    The better CYA tests are +-10 under ideal conditions, and much more commonly +-20. Most of electronic testers, including both of the ones commonly used by pool stores, are significantly less precise than that. Plus there is plenty of room for operator error on the CYA test.

    The only way to really know what is going on is to purchase some calibrated CYA reference solution (Taylor R-7065) and test that with the different tests.
    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

  5. Back To Top    #5

    Join Date
    Dec 2010
    Location
    San Diego, CA
    Posts
    1,129

    Re: CYA Test Accuracy

    Jason just beat me to it, but here's a link to where you can buy the R-7065: http://tftestkits.net/R-7065-CYA-Sta...ution-p34.html

    I had the same concerns as you; so I bought this standard as well as a large bottle of CYA refill (http://tftestkits.net/R-0013-CYA-Refill-8-0z-p52.html) so that I can run the test as many times as I want without running out of reagent.

    I always run the standard solution first to calibrate myself for the conditions (amount of sunlight, etc.) I used to read the standard at 60-70 until I played around with how high to hold it, where I stood in my yard (I have two different colors of concrete), how bright the sun was that day. Consistency is key! I got pretty good at it actually in the summer. However, come winter and cloudy skies and my ideal conditions were no more, so I found myself recalibrating to a new position, etc. Same thing for time of day - I couldn't always measure at 10am, and the sun's location changes throughout the year. Is this overkill/ridiculously anal retentive of me? Yes, but this is what I've done to feel confident in my testing.

    Just my $.02 but with CYA being so key to the TFP/BBB method I think it is well worth it to get the standard solution.
    15,600 Gallon, 16' x 32' In-Ground Vinyl Pool
    Pentair VS 3050 pump, Quad DE 60 filter and SunTouch controller
    8 gallon Liquidator, Aquatherm EcoSun Solar Panels, 2 wheel ThePoolCleaner

  6. Back To Top    #6
    Mod Squad woodyp's Avatar
    Join Date
    Apr 2010
    Location
    East Texas
    Posts
    9,000

    Re: CYA Test Accuracy

    You guys been holding out on me! (or most likely I just missed it) First time I've ever seen anything about a "standard solution" mentioned. Anything to help me get a more accurate reading would be a blessing. Off to order some now. THANKS!
    16x32x52" Steel Cornelius Miramar AGP Vinyl liner 13,100 gal. Buried 2 ft.
    2 Speed Hayward Power-Flo Matrix 85 g.p.m. 22" 250lb. sand filter hard plumbed
    Pool Rover Jr., Pool Blaster Max, Diver Dave TF100 Test Kit/Speed Stir
    Margaritaville Frozen Concoction Maker, Liqour Chiller, & Drink Mixer & Party Tub----Collect 'um all!

  7. Back To Top    #7

    Join Date
    Dec 2010
    Location
    San Diego, CA
    Posts
    1,129

    Re: CYA Test Accuracy

    15,600 Gallon, 16' x 32' In-Ground Vinyl Pool
    Pentair VS 3050 pump, Quad DE 60 filter and SunTouch controller
    8 gallon Liquidator, Aquatherm EcoSun Solar Panels, 2 wheel ThePoolCleaner

  8. Back To Top    #8

    Join Date
    Sep 2007
    Location
    Guelph, Ontario, Canada
    Posts
    56

    Re: CYA Test Accuracy

    Thanks to all for the great response.
    I guess I need to buy some standard solution.

    Two questions.

    1) Does the CYA standard have an expiration date? I'll likely only test CYA every couple weeks ( 8-10 times/ season)
    I'm not quite sure if carlscan26 is suggesting that I mix the CYA 50ppm standard with R0013 and keep in it a separate bottle so I can use it over and over throughout the course of the year? or just recommending I order the large bottles to make sure I'll never run out.

    2) Does TFTestkits ship to Ontario, Canada?
    Carl Schnurr
    Pool: 96,000 litre, vinyl liner, 1 HP pump, sand filter, Aqua-rite SWG, Hayward e.vac, installed 2005
    Spa: La-Z-Boy 'Relieve', 1300 litre, acrylic, with ozonator, installed 2017

  9. Back To Top    #9

    In the Industry

    duraleigh's Avatar
    Join Date
    Apr 2007
    Location
    Sebring, Florida
    Posts
    30,084

    Re: CYA Test Accuracy

    The standard solution is available for CH (200ppm), CYA (50ppm), and TA (100ppm). They have no expiration dates.

    However, Taylor Technologies does not allow any of it's customers to ship any Taylor product into Canada from the US.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  10. Back To Top    #10

    Join Date
    Aug 2007
    Location
    Hunterdon County, NJ
    Posts
    28

    Re: CYA Test Accuracy

    Although it wouldn't be as accurate as R-7065, for those outside of the U.S., is there a way to create a reasonably accurate reference solution using tap water and CYA powder?
    31,000 gal gunite/Pebblesheen pool w/spillover spa, 2-speed 1.5 HP filter pump, 3 hp spa jet pump, 2 hp sheer decent pump, blower, DE filter, Jandy automation and SWG, Jandy 400K BTU gas heater, Polaris 280 cleaner with booster pump.

  11. Back To Top    #11
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: CYA Test Accuracy

    There is no easy way to produce a sufficiently accurate test solution without laboratory grade equipment and laboratory grade chemical supplies.

    The Taylor calibration reagent is available world wide, however prices are sometimes far higher and you may have to search fairly hard for people who import it to your country.
    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

  12. Back To Top    #12

    Re: CYA Test Accuracy

    I know I am new to TroubleFreePools but I do have some experience in running tests that use the "black dot" method. The key is to control the light shining through the vial as well as the ambient light.

    I plan to use the light from my speedstir and conduct the test in a room where I have total control over the ambient lighting. This should enable me to have consistent results. Now that doesn't guarantee the results themselves will be accurate but they should at least be consistent.
    33ft Round AGP (24.5K gal), Waterway Hi-Flo 1.5 hp/2spd DE filter

  13. Back To Top    #13
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: CYA Test Accuracy

    The CYA test needs very bright light. I doubt that your average indoor light or the speedstir will be nearly bright enough. Some pool stores use a small daylight simulator, but they can be expensive.
    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

  14. Back To Top    #14

    Join Date
    May 2007
    Location
    Montreal Canada
    Posts
    326

    Re: CYA Test Accuracy

    See last post in this thread:
    cya-testing-t34850.html

  15. Back To Top    #15

    Join Date
    May 2007
    Location
    Montreal Canada
    Posts
    326

    Re: CYA Test Accuracy

    cschnurr, I'm sending you some Standard Solution.

  16. Back To Top    #16

    Join Date
    Sep 2007
    Location
    Guelph, Ontario, Canada
    Posts
    56

    Re: CYA Test Accuracy

    Thank you Paul (CaOCl2), your the best.
    I'll post my results along with the PS testing of the solution once the weather starts to look like swimming is on the horizon.

    For anyone looking for Taylor reagents in Canada, Apollo Pools in Montreal has a website at
    http://piscines-apollo.com/cubecart/index.php, they have always been prompt, and reliable.
    Carl Schnurr
    Pool: 96,000 litre, vinyl liner, 1 HP pump, sand filter, Aqua-rite SWG, Hayward e.vac, installed 2005
    Spa: La-Z-Boy 'Relieve', 1300 litre, acrylic, with ozonator, installed 2017

  17. Back To Top    #17
    lefty51's Avatar
    Join Date
    May 2015
    Location
    East of Royals country western MO
    Posts
    451

    Re: CYA Test Accuracy

    Quote Originally Posted by JasonLion View Post
    The better CYA tests are +-10 under ideal conditions, and much more commonly +-20. Most of electronic testers, including both of the ones commonly used by pool stores, are significantly less precise than that. Plus there is plenty of room for operator error on the CYA test.

    The only way to really know what is going on is to purchase some calibrated CYA reference solution (Taylor R-7065) and test that with the different tests.
    Hi Jason, I hate to bring up an old thread. But with this lack of sunshine this month and being new to the TF100 CYA test, I'm trying to figure out a lighting setup where I can test CYA on days like today. I know, more POP !

    I'm waiting for FC to drop back down to test PH and I'm bored

    Anyway the question is, if I get the reference solution and use it to compare with my solution is it possible to setup a lighting situation that would be accurate and repeatable.... providing my bulb did not burn out and replaced it with a different wattage ?
    Si -central Mo. 32' x 16' -- 3'4" to 6' deep Vinyl liner - 16,500 Gals : Triton II filter -Duraglass 2 hp pump - 1 speed : SI-30 salt generator
    TF-100 with speedstir

Posting Permissions

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