ICE is just expensive Water :B
It does not scrub the tank.....just floats, bounces around and melts
LINKAs for those sensors......
SeeLevel stay cleaner longer because they don't come in contact with 'stuff' but the inside of tank does get crudded up.,
Soap scum, dried on TP, dried on poop, body oils etc.
So what do you use to clean tub/showers at home.
CLR, Kapow, Purple goo etc.
Problem is you can't spray those on the walls of waste tanks.
So you need a digester.....Unique is one brand that will break down stuck on stuff.
Personally...I don't bother. I dump when necessary w/o looking at useless monitor.