I am getting consistant differences with my TF-100 and the local pool store (they assure me fresh Taylor test chemicals). I am doing lots of tests as I am in the process of adding salt for a Pentair IC40 install next week.
My TF-100 Reading:
PH-7.2 (I have added dry acid twice in the past week to bring it down)
Pool store readings:
FC-5 (they don't do the drop test)
Salt - 2000 (after 6/45lb bags of salt) - I plan to add 3 more which should bring me close to 3400
I bought my TF-100 last year so all the chemicals should be good, only difference is 15 minutes of sitting in the bottle. Any thoughts?