Discrepancy between pH strips and drops

[kjdo]

Please start a new thread for your own questions. Thanks, jblizzle

I have been using the TF-100 test kit for everything except the pH and a Chem-Tek 5 way test kit for the pH (because it has the ability to adjust for high chlorine levels). However, this year I am nervous about the discrepancy noted on the pH between the test strips (getting a 7.2) and my Chem-Tek 5 way. (getting a 7.8). My gut says to trust the Chem-Tek drops, but I don't understand why the test strips are reading so low. :?:

any thoughts?

 

[jblizzle]

Chem-Tek 5 way test kit for the pH (because it has the ability to adjust for high chlorine levels).

I do not think this is true. The Taylor test is capable of pH testing up to a FC level of 10ppm and I am not sure any other manufactures are better able to adjust for chlorine.

However, this year I am nervous about the discrepancy noted on the pH between the test strips (getting a 7.2) and my Chem-Tek 5 way. (getting a 7.8). My gut says to trust the Chem-Tek drops, but I don't understand why the test strips are reading so low. :?:

How old are the strips? I would throw them away and trust any drop based test over them. And why not just use the pH test that came with the TF-100?

You could do an experiment like this and see if the Chem-Tek does any better than the Taylor:
accurate-ph-test-during-shock-levels-with-r-007-t61076.html

 

[kjdo]

OK. I did test the Chem-Tek against the Taylor 100 and the Taylor 100 is 7.2 like the test strips and the Chem-Tek is 7.6. I assumed it was because of the chlorine level being above 10 (it is 13). I will test again tomorrow night and report back. This has been a very frustrating year for me with the cool weather, the pool cover closed more than open, the pH and alkalinity acting quite different from last year. (I had another question/thread a month or so ago about this issues so I will not belabor this point.)