DutchmenSport wrote:
Assuming this is a new camper for you, in time you'll quit using the sensor readings completely. Why? Because in time, you'll know how much water you can use, and as you get more familiar with the camper, it just becomes second nature to keep a mental track of how often things get used, especially water usage. You'll just know when it's time to fill the fresh water tank and dump the holding tanks.
As far as the black tank goes, most camper have the toilet with the foot pedal and the slide valve in the bottom of the bowel. Every time you push that pedal, you can look down the hole and see how full the tank is. Here again, it takes a few times to learn it, but it does happen.
I very seldom use my sensors any more, but after 5 years of owning this camper, the original factory sensors still work. I attribute that to towing the camper with little water in the black tank and the dish washing liquid. And I actually tried them last night, and still work (showing empty right now, which it is.)
good advice here
over time you will learn how many days you will average on both black and grey tanks. especially if the same number of people camp with you trip by trip
always just my wife and i so i always can judge pretty close to accurate.
always good advice to never dump black tank until its 3/4 full to full and always start a trip with some water (i usually pour about 4 or 4 gallons in the black tank before we leave home for a trip)