I upgraded to a Taylor K-2006 this season. I 've used walmart kits and strips in previous years.
I ran though my first round of testing with the K-2006 today and I have a few questions.
Here's the FAS-DPD procedure given in my kit:
1 - Add two spoons of R-0870 (DPD- Powder) to a sample and swirl till mixed.
2 - Add R-0871 (FAS-DPD Titrating Reagent) dropwise counting drops until color changes from pink to colorless.
3 - Add 5 drops of R-0003 (DPD Reagent #3). Swirl to mix. Solution will turn pink if there is combined chlorine.
4 - Add R-0871 (FAS-DPD Titrating Reagent) dropwise counting drops until color changes from pink to colorless.
My problem is that while doing step 2 my solution would go crystal clear but if I waited 20-30 seconds the solution would turn deep pink again. I reran the test thinking something was wrong. It happened again but I had no idea what to do. I saw two options:
#1 When dropping and swirling do it fast! As soon as the solution goes crystal clear stop adding drops. If the solution turns pink again ignore it.
#2 Once the solution goes crystal clear wait a minute. If it turns pink then continue adding and swirling.
So which is it?
There's room for interpretation in the Total Alkalinity and Calcium Hardness tests too. In both cases, my color changes occurred over a series of drops. It was 2-3 drops between the beginnings of change and a full, deep final color. Where do you stop? When none of the initial color is left or when the final color is full and deep?
I have to comment on the amount of reagent provided for Cyanuric Acid testing. Unless I'm missing something, there's only enough for six tests! I would think that a $70 test kit would provide at least twice that if not more.
There was a pleasant surprise in the K-2006 though. The little booklet titled "Pool & Spa Water Chemistry" turned out to be a fun and informative read!