Hello TFP Team,
I have not yet verified this since the pool is currently closed..I may add some chlorine to tap water to confirm. Taylor offers the K-2005 and the K-2006. The main difference between these two kits is that the 2005 is liquid DPD and the 2006 is powdered DPD with FAS liquid. My question is why can I not combine the two together for a perfect kit?
In the 2005, you add DPD 1 to DPD 2 to develop a shade of pink, which is then compared using a comparator to get your free chlorine level (Not to be confused with orthotolidine tests which are generally yellow in color). Then, to find combined chlorine, you add DPD 3 which would turn the sample more pink giving you a total chlorine reading. You then subtract the two samples to get a combined chlorine reading.
In the 2006, you add two scoops of DPD powder (R-0870) to develop a shade of pink. Then, using R-0871 drop wise, you turn the sample clear and record your result. To find combined chlorine, you add the same chemical as used in the 2005, DPD 3, and turn it clear once again using R-0871.
Why can I not use DPD 1 + DPD 2 to get my pink sample instead of using DPD powder? Now that I have my pink sample using only liquid, I can then either follow the directions for the K-2005, matching the color, or the K-2006, adding R-0871 drop wise etc... You think that would work? My problem is that DPD powder has a questionable shelf life when used frequently. It starts to cake up and turn black. It would also be nice to have two options. Using the comparator for a fast glance, or using the drops for a more accurate answer without having to perform two tests.
Check out the ingredients for DPD 1 + DPD 2 here.
Check out the ingredients for DPD powder here.
See a similarity?