Added to turn total dissolved solids from an occasional hand measurement into a continuous trace, so the creep between water changes could be observed rather than guessed at.
What I've learned
·The trace makes each water change visible as a sharp drop, which turns the change schedule into something driven by measurement rather than the calendar.
·Conductivity is logged continuously; hand-tested TDS is kept separately as a cross-check.
Installation
Not yet documented.
Configuration
·EZO Conductivity K0.1 on a USB carrier board
·Read every five minutes into the time-series log
·Calibrated against a K0.1 solution set (84 / 1413 µS/cm)
Maintenance
Not yet documented.
Known limitations
Not yet documented. Absence here means nothing has been written down, not that there are none.
Controller integration
Read by the Raspberry Pi over a USB carrier board every five minutes, independent of the controller.
Calibration
Calibrated with a K0.1 solution set (84 and 1413 µS/cm), kept as a tracked inventory consumable.
Current observations
·Continuous trace in place; each water change shows as a step, and the creep between changes is visible.
What this item is doing now, as distinct from what has been learned over time.