With our Forester Class C 31ft, our black tank sensor was very unreliable so we would be in the habit of dumping our tanks at the endvof any trip and that would usually be about 3 days. Also if you are not able to flush your toilet then you better dump fairly quick. Its not a perfect science but we were conscious of it and always made sure we rinsed out our black tank after dumping it. Good luck and have fun!
__________________
|