Before I ask my question, I realize that a lot of people are in favor of the Taylor (and other) test kits. Given that I'm color blind and was struggling to identify if pH was in range or not I went ahead and ordered the water spin.
All measurements seem very accurate when comparing to the test kit (my wife verifying the colors). However, pH seems to be different. In an effort to verify the accuracy of the WaterSpin I used a disk, put in 6.9 pH calibration solution that the labs use and it was right on the money, there number was 6.89 and the WaterSpin was 6.9 (only one decimal place is shown in the LaMotte software).
First, is the use of a calibration solution at 6.9 pH a way to verify accuracy of a device? The taylor test kit doesn't go that low, it stops at 7 and goes to 8.
Would it be reasonable that the pH shown on the WaterSpin is accurate at 7.8 when analyzing the pool water even though the taylor test kit is showing 7.6? I'm not familiar enough with the taylor kit to know it's percent accuracy.
I don't want to put to much acid in the pool and I'm trying to keep the pH between 7.4 and 7.8.