[Delphinus]

I recently chose Tunze for this on the basis that my sumps have traditionally been places that feather dusters and brittle stars reproduce like crazy and they get into and onto everything down there, and I could see that gumming up a float switch based sensor. The Tunze uses an ultrasonic sensor with no moving parts so I am hoping it will be less prone to troubles from the little critters.

That said I can see that it still needs to be kept clean, I can see that a slight film forming on it would probably gum it up just as bad.