I have a 40 gallon fresh water tank. We took 2 quick showers, a few toilet uses and a small dish washing and my tank was showing empty. What is the average dry camp water use? Seems to us, 40 gallons ...
X2 for looking at your tank. I never trust the sensors. If it says 1 light I go out and open the compartment to look at it. Usually at 1 light I have about a 1/2 tank left. The sensors are weird. Don't trust them...take a look for yourself and use as little as you can. We also take a 7 gallon jug with us and sit it on a table outside for washing hands and faces as necessary. This saves a lot of water.