I'm stuck on a ph testing issue and I'm not sure how to proceed. The core of the problem is conflicting readings. This is for a plaster indoor pool with bromine chemistry (alas, due to a built-in hot tub), water @ 84F. The pool has been covered & unused for about 2 months. Normally, when balanced and unused, it can go for months without the chemistry getting out of whack.
- Measure 1: 7.5. This is done with Taylor K-2006 purchased August, 2014 from Amazon.
- Measure 2: 7.4. This is done with Taylor K-1004 purchased August, 2014 from Amazon.
- Measure 3: 7. This is done with Milwaukee MW-102 which pegs a 7ph Atlas reference liquid less than a year old at 7.05.
My gut tells me that the Milwaukee is right because of the reference liquid measurement. Those things are made for labs. However, both Taylor tests agree closely and also have relatively fresh chemicals.
The bigger question is, if I can't trust the Taylor ph tests, how can I trust their other tests? For example, both test kits read TA at 140 now while I normally keep it in the 100-110 range.
I'd appreciate some advice on how to proceed...