Anyone have tips for mounting to the surface of the tank?
To the tank, both the sensor probes with the meters and the DS18B20 I have made up from the IC's themselves, use HVAC aluminum tape to fix the sensor or the DS18B20 to the tank surface. The tape works well, haven't noticed any coming loose. To pipes, the same think, but also cable ties. In all cases good insulation. My sensors have been installed for at least two years now, not known problems.