Join Date: Sep 2012
Location: Atlanta, Georgia
I have a cheap-o one I calibrate it with 7.01 solution. It seems pretty accurate. I have tested it against API tests and the same results. Mine has a problem with the digital read out, the last 2 are missing unless you squeeze it just right. So if the pH is reading 7.1 you would not see the 1 at all. I don't trust it but for daily testing it is close enough and in my opinion as reliable as most multi test strips I have tried. Try calibrating it with only the 7 lab grade since hopefully you will not need it to be accurate below 5. See if that works.