I got a strange thing going on with the PH readings I have been taking for the past week. I just happened to stumble on to it when I tested the water and got a low PH reading around 7.2, I retested with the same sample water in the same bottle and the PH 7.8, because I suspected that it wasnt right. I then tested again and again with same water on got 7.8.
Now everytime I test my PH the same thing happens. I have tried taking sample water from different locations with the same results. First test 7.0 approx, all tests thereafter 7.8( with same sample water). I am every careful in rinsing the test tube before and after each test. I gather water from as deep as i can. Could it be an issue with the reagent. It's a year old, been keep in the house in the closet(cool location). Never stored in direct sunlight or outside.