very nice. So it's a tester+controller? it doses alk to the system if the measurement alk is below the desired setpoint?
I love the pump calibration menu. That's very simple and nice. I worry about systems like this getting too complex to easily bugfix for the end user. But yours seems very transparent at all steps.
For the alk test itself, you are dosing acid and measuring pH to the endpoint of pH 4.5?
Yerp just a clone of Randy's test. It uses an offset that I have added in since. This allows you to tune it to your dkh to your test kit for cross reference. And a few other bits and bobs like manually dose alkalinity amount.