May I ask what you are using to test the tank water that you use to calibrate the Trident? Are you using the values of your last test using the Trident, or a 3rd party test kit? If so, which one?
Thanks!
They are using their preferred manual test kit. They run a test, hopefully three, get the value, and use that to plug into the calibration task on the Trident. A few believe that the included calibration solution that comes with the reagents is not good or correct.
I can only speak for my experience and find it to be accurate.