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Testing kits

October 6th, 2003 · 3 Comments

I have a water testing kit with no instructions. It has two sides: pH
(phenol red tablets) and Cl (DPD tablets).
The pH side is fine, the tab dissolves instantly and my water is
about right (7.4-7.6).
However, the DPD tab takes forever to dissolve and shows a low
chlorine content BUT if I leave it for a few hours and look at it
again, it has gone darker, possibly indicating a higher chlorine
concentration than I at first thought - which reading do I believe??
Thanks
Nick.

Tags: pumps

3 responses so far ↓

  • 1 janis_40 // Oct 8, 2003 at 4:51 am

    I do not know what brand of test kit you have but I think there is one on the
    market that the first indication of chlorine is free chlorine and the second
    is total chlorine. This is with one tablet. Other test kits require two
    tablets for free and total chlorine. If you know who makes it the
    manufacturer may have a web site.

  • 2 Neva Marjory // Oct 8, 2003 at 6:18 pm

    One tablet is for the ph test (phenol red) and the other tab (DPD) is
    for free chlorine I believe. The question is, how long I should leave
    it before reading it?
    Nick

  • 3 janis_40 // Oct 9, 2003 at 7:48 pm

    That depends upon the test kit. For a normal kit you read it when the tablet
    is gone. But again we need to know what brand the kit is.

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