Pool test smackdown: Taylor K2006, OTO, Pinch-a-Penny, Pool Store

[AnnaK]

So here's the question: When I add the reagent drops to the K-2006 that change the water color from pink to colorless, is the objective to really get it to be 100% colorless, or just mostly colorless with perhaps a slight tinge of pink still remaining? How colorless do you strive to make the water during this test?

There are no gradations of 'colorless'. It's an absolute. Colorless = absence of color = clear. A slight tinge of pink means there's still color and you're not done with the titration. Keep adding and counting drops until it is colorless.

[famousdavis]

AnnaK,

Thanks for the "clarity" of your answer. :-) I wasn't sure just how sensitive the drop testing process is. I guess it's pretty sensitive. Usually when I get to what I think is the last drop, because it looks pretty clear already, I'll add one more drop of the reagent, and then it gets noticeably more white. To paraphrase Horton, A trace is a trace, no matter how small.

[AnnaK]

All the way to infinity, yeah. But we don't need that sort of precision. When it doesn't get any more colorless you subtract all the drops you added to see if it would and then use that number in your calculation.

Clear?

[famousdavis]

Very clear!

One question, though: If I add another drop to see if it gets clear (during the FC test) -- and it doesn't get any more clear, because it's clear and colorless already -- does that extra drop of reagent goof-up the subsequent test for CC? I'm thinking it wouldn't matter, but I really don't know that for sure.