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Thread: Drastically different FC readings with 10mL vs 25mL sample on Taylor K-2006

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    HouTX's Avatar
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    Drastically different FC readings with 10mL vs 25mL sample on Taylor K-2006

    I have been using the 10mL testing method with consistent results over time. I decided to use the 25mL sample today as I have been tweaking pump run time and SWG % over the last week to accommodate heavier usage. To my surprise I had to add 32 drops (x.2) using the 25mL method giving me a result of 6.4ppm vs 3.0ppm using the 10mL sample.

    I tested again using 25 mL sample and I was at 40 drops with the water still a very faint pink. I verified results with a different DPD test previous owner had left behind, and a test strip. The chlorine is consistent at 3ppm across all tests vs the 6.4-8+ ppm using the 25mL sample. What would cause such significant variations between sample size ?

    Here are the rest of my readings:

    CC .5 (10mL) & 1+ (25mL)
    pH 7.5
    TA 75
    CYA 50
    CH 350
    30k Gal, IG, PebbleTec, Jandy: CL460 Cartridge Filter, SHPM2.0 Pump (Filter+Spa), SHPM1.5 (Waterfall), spill-over SPA, PLC1400 SWG, LXi400 Heater. Polaris Caretaker Infloor Cleaning system, Jandy PDA-PS-8 remote, Taylor K-2006 Test kit

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    Azgirl71's Avatar
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    Re: Drastically different FC readings with 10mL vs 25mL sample on Taylor K-2006

    I would just stick with the 10ml test. I don't really have an answer for you other than you are just wasting reagent when you use the 25ml test.
    Lisa
    Intex AG vinyl 15' x 48" 4,300 gallons due to skimmer install, Krystal Clear SF pump combo 2800 GPH, Krystal Clear SWG, Pool Blaster Max vacuum, Hayward thru the wall skimmer, TF 100 test kit with speed stir, K 1766 Taylor salt test, My SLAM Process

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    Shallotte, NC
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    Re: Drastically different FC readings with 10mL vs 25mL sample on Taylor K-2006

    Sort of a short answer is: your technique. Read this and see if anything pops out: http://www.troublefreepool.com/threa...Kit-Directions

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    Mod Squad jblizzle's Avatar
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    Re: Drastically different FC readings with 10mL vs 25mL sample on Taylor K-2006

    My guess is not enough swirling.
    Jason, TFP Moderator
    18k IG pebblesheen pool, Hayward ProLogic P4 w/ T-15 SWG, Pentair 1HP 2-speed Superflo, Hayward 6020 DE filter
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    Pool School + Test Kit + PoolMath = A TROUBLE FREE POOL
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