Help with contactless water sensor for Arduino

[Brian]

Could such a sensor be used to detect a slow draining sink?

Volunteer Opportunity: Sink Trap [Filled]

Hey folks, I think it is time to change the clay trap again! I’d really like to have a new person each time so we can build a small group with the know-how. (It’s super easy.) I’m pretty flexible to meet up with someone, available both days and evenings. I keep an eye on that sink so I’m ready to change the trap bag before it becomes a problem. The other day it was draining really slowly so I inspected the drain. It was clogged with random bits of grunk, newspaper and spinach leaves(!). It is …