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Thread: Saving Test Chemicals

  1. Back To Top    #1

    Join Date
    Apr 2015
    Leesburg, GA

    Saving Test Chemicals

    Tips on this site are saving me $$$ in many ways. Here's a good one:

    For the FAS-DPD Chlorine Test I have been using the 25 ml sample size with my K-2006 kit. The 10 ml sample size is mentioned in the instructions as an alternative but the 25 ml sample size is featured more prominently in the instructions so I have been using that size without much thought about it. After reading instructions on this site it caused me to reconsider the way I was doing the test.

    My FC level this morning measured 6.5 ppm. The following is an example of what I formerly did and what I do now.

    I used to always use the 25 ml sample size and put in two dippers of the powder. Assuming my FC level was 6.5 ppm I would have had to put in 33 drops of R-0871 reagent to determine that particular FC level. Granted, the 25 ml process gives more resolution (0.2 ppm vs 0.5 ppm) and my FC level may have measured 6.2 with 31 drops of reagent but it could have also measured 6.6 with 33 drops. The point is unless you are doing the overnight FC loss test the 0.5 ppm resolution should be all the precision that is needed in most cases.

    This morning I used the 10 ml sample size. I put in less than a full dipper of powder and noticed my sample quickly turned a bright red/pink. I was satisfied that I did not need more powder. I then started putting in the drops of R-0871. My sample turned clear with 13 drops!

    Old method required two dippers of powder and 33 drops of R-0871.

    New method required less than one dipper of powder and only 13 drops of R-0871.

    Eye opening isn't it?
    20' Intex; 52" deep; 8,638 gal; above ground. Intex 1,600 GPH sand filter.

  2. Back To Top    #2
    Mod Squad Patrick_B's Avatar
    Join Date
    Jun 2011

    Re: Saving Test Chemicals

    Yes indeed. Time and again I have compared the 25 against the 10, and there is so little difference, it matters not one iota.
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