Great suggestions and tips, thanks Rene! I’ll put some extra time into designing the implementation of that turbidity sensor, I have a few ideas but zero experience with actual tests. I assume the same issues apply, maybe more so, with cheap flow rate sensors like this: https://thepihut.com/products/adafruit-liquid-flow-meter-plastic-1-2-nps-threaded
I would imagine they may provide some initial indication of flow but shortly after are almost useless due to deposition/foul.
Temperature by itself can be pretty useful though, so I’ll start there.