Questions about FC and CC test with Taylor K-2006

[gwtw]

I have some questions about the chlorine test that came with my new Taylor K-2006 test kit. I have noticed that if I swirl more vigorously after adding each drop for the FC test, the pink color in the water goes away faster. It makes me wonder just how accurate this test is since it can be affected by how vigorously you swirl it. I tested it two times awhile ago and I got a different result both times. The first time I tested it, the pinkness didn't go away by gently swirling it until I put 20 drops in. When I repeated the test and swirled it a little more vigorously, it only took 12 drops before it cleared up completely. Just wanted to know how vigorously I need to be swirling it. Also, today when I added the 5 drops of the reagent for the Combined Chlorine test, the water in the vial stayed clear but it had a slight pinkish cast to the very top of the water line. I added one drop of the necessary reageant and this slight pinkish cast to the top of the water line immediately disappeared. Does this mean that I have 0 CC or .2?

 

[mknauss]

Are you using a 10 ml water sample for the FC test? That is all you need. Each drop of reagent counts for 0.5ppm FC.

Not sure about the swirling. I have always had a SpeedStir. Wonderful device. Does the swirling for me. Be sure you are not adding the drops quicker than one per second.

 

[gwtw]

I'm using the 25 mL sample because the instructions on the Youtube said to use the 25 mL sample if you were expecting a smaller chlorine level. I have a feeling that swirling more vigorously is the way to go because I got closer to the number that I was expecting. I thought this test was supposed to be very accurate so it bothers me that the results can differ depending on how vigorously you swirl the vial.

 

[cfherrman]

When you add the powder are you useing heaping scoops? Is there a little powder left on the bottom?

 

[gwtw]

I have now done two tests back to back on two separate occasions and I saw inconsistencies both times. When I tested twice last night, it took 20 drops before it got clear (4.0 chlorine level), and the second time, it only took 12 drops before it came clear (2.4 chlorine level), which is a huge discrepancy. I added 2 heaping teaspoons of the powder both times but I shook it a little bit more vigorously when adding the drops when I got the lower reading. This morning, I tested it twice back to back again, and I tried to swirl with the same amount of force both times. The first time, it took 24 drops before clear (4.8 chlorine level), and the second time it took 26 drops before it came clear (5.2 chlorine level). These inconsistencies concern me because if I do the OCLT test at night and accidentally shake the vial more or less vigorously in the morning than I did in the evening, it could throw off the results, just like it did the first time I tested it back to back. Would I get more consistent results if I swirl it a little bit up and down and then side to side or is gently swirling it side to side all that is needed? Do you get better results if you add a drop, swirl for 2 seconds, and then add the next drop, instead of slowly adding each drops while swirling consistently the whole time? I can't afford to waste any more solution testing back to back again so any advice would be greatly appreciated.

 

[RobertScalchi]

These are all good valid questions I would like to have answered as well.
I have with the k2006 fas dpd always used 2 level scoops, used the 10ml to save reagent, and added drops until the sample was just on the verge of completely clear with a slight pink twinge to it, added one more drop to get clear, and made my recordings. I noticed once it turned clear if I left it out for a little while, the clear would fade back to a pink twinge.

Same goes for the TA and CH test.

 

[gwtw]

It says in the instructions that you should use the 25 ml sample if you are expecting a lower chlorine reading. Will you get an accurate reading if you use the 10 ml sample if you are expecting a level between 1-6? If so, I'd love to start using the lower amount to save on reagent since I just wasted a bunch of it testing back to back on two separate occasions. Has anyone tested using both a 25 ml sample and a 10 ml sample with the same pool water and got similar results with lower levels of chlorine in their pool?

 

[mknauss]

For the purposes of pool water chemistry the 10 ml sample is all that is needed.

You should not shake the sample. Swirl it. I highly recommend the Speedstir.

 

[cfherrman]

I swirl with my lright hand and drop with my right counting at the same time.

Use the 10 mil sample, the 25 mil is good for a Overnight Chlorine Loss Test