Bought a $16 meter from gravity lips
Calibrated meter to 7.3 using the pool water which was calibrated recently.
Tap water is reading 8.0
Bought pure dew ultra pure water to calibrate using the 4.00 and 6.86 sachets, however it reads 9.0
Distilled tap water using a jug in a boiling water pot with the lid inverted filled with ice, reading is 7.5
