Two tanks, one valve. Both tank indicators fill up at the same time and both empty at the same time...been using this camper for a year, only ever used the one and only grey dump valve. My only question was did I have 56 or 76 gal of holding. Now I know it's 76.
Tanks are mounted side by side and while I cant see everything it appears that the outlets come off the inside towards the rear of the tank/trailer and meet into one 3 or 4" pipe.
Actually not silly to me at all, why would one want two separate tanks when one can connect them and have only one to worry about filling and emptying?
Here's the pic. I tried to add arrows depicting the direction of flow and I overexposed the pic to better see the black pipe