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Thread: DPD testing instructions that uses less reagent

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    DPD testing instructions that uses less reagent

    I know at some point I read instructions on a way to do the DPD chlorine test for high levels of chlorine where you use less reagent. I can't find that post now... does anyone know what I mean? It was something like use a 25ml sample and multiply by .2 instead of .5, but I want to make sure I get it right. Thanks.
    Sue

    18' round Sharkline Matrix AGP / 8600 Gal. / sand filter / Aqua Trol SWG
    Pool owner since 2001. Thanks to TFP for helping me convert off Baquacil after six years!

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    JasonLion's Avatar
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    I am assuming you mean the FAS-DPD test, the one that starts with a small scoop of power turning the water pink.

    Using a 25 ml sample and multiplying by .2 requires more reagent than usual.

    You can mix the pool water one to one with distilled water and test that. Then each drop will be 1.0, which means fewer drops and a faster test but you lose precision.
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    Yes, that is the test I meant. Thanks!
    Sue

    18' round Sharkline Matrix AGP / 8600 Gal. / sand filter / Aqua Trol SWG
    Pool owner since 2001. Thanks to TFP for helping me convert off Baquacil after six years!

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    MikeInTN's Avatar
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    You can also fill the tube to 10 ml; then each drop is .5 ppm.
    24' x 52" AGP - approx 13,500 gallons
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    Quote Originally Posted by MikeInTN
    You can also fill the tube to 10 ml; then each drop is .5 ppm.
    That's the way I usually test. I have never really felt that I needed the accuracy of 0.2 ppm. Saves me on reagent which is good since nobody around these parts carries R-0871.
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    MikeInTN's Avatar
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    Quote Originally Posted by 257WbyMag
    Quote Originally Posted by MikeInTN
    You can also fill the tube to 10 ml; then each drop is .5 ppm.
    That's the way I usually test. I have never really felt that I needed the accuracy of 0.2 ppm. Saves me on reagent which is good since nobody around these parts carries R-0871.
    I bought a pretty good sized bottle of R-0871 online from these folks Swimming Pool Supply . In fact, I use them for all of my refills. The reagents are shipped direct from Taylor Technologies.

    I'm thinking i got the 2 oz bottle of R-0871 (it's DPD#2 on the website, I think).
    24' x 52" AGP - approx 13,500 gallons
    Pentair Optiflo 1 hp/2sp pump w/ Swimpro Voyager 150 sq ft cartridge filter
    Intex 8110 SWCG
    "Fear the Schnauz!"

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