first, the majority of us that have tote tanks, use it strictly for GRAY water, NOT black water.
not saying you can't but the gray tank will fill way faster than nearly any black tank, in comparison.
so, i don't have to have such worries, since i would never use mine for the black water. it would take us several weeks of camping, to fill our black tank, whereas we'd be lucky to go 5 days before the gray tank would be full.
are you a new RV owner, because many newbies focus on the black tank, when it should be the gray tank you should be focusing on.