erratic figures

[voodoo]

hiya guys need to seek opinion/advise > Ph test pen.
have this HANNA instrument Ph test pen for a while, working fine in the beggining but recently it start to show Ph rnage jumping from 7.8 down to 6.8 and then up to 7.2 and then down.. it wont stay still. holding it in water for almost 15 min.dang! calibrate it in PH 7 solution it show 7 excatly! soot! is my water problem? or my PH test pen wracked? or time to empty my wallet?[]

[David]

Hi voodoo

I think you need to calibrate at PH7 and PH4......