Starting with empty tanks.
So we get to the campground and pour in our favorite odor and/or decomposing additive.
We add a gallon of water. The water washes the additive into the drain pipes under the camper.
Then we go about camping and using the sinks and toilet. "Stuff" lands in the bottom of the tanks and lays there, because the additive and water are sitting in the drain pipes. . Stuff stinks!
Eventually enough liquids are added to cover the bottom of the tanks, but nothing has really stired up the additive/water mix in the drain.So how much of the additive will migrate to where it is needed, to where the stuff is ?
Wouldn't it be better to first put enough water into the tank to fill the drains, before pouring in the additive/water mix? How much liquid does a 3"-4" pipe hold per foot or inch"?