If you’re suggesting immersion sensors, you might find a common 5V is harder to implement than you think.
Insulating the U-shaped container in all circumstances will be a lot harder than expected.
Possibly, grounding the container 0V will be a lot easier, and adding positive bias to the depth probes will make more sense..
Keep in mind any voltage will expose the project to the possibility of spark ignition, and cathodic effects.