[Bob Landry]

If there is a dump valve handle for each grey tank, then they are not plumbed together. You will also find that one will fill a lot faster than the other. My solution to this is to keep the main dump valve shut off, as well as the black tank valve, and open the two grey water dump valves. This allows the tanks to fill at the same rate since water is going to seek it's own level in each tank. I do it this way so when camping for several days in parks with no sewer hookup, I only have to dump the grey tanks in the blue tote and haul grey water every three days or so. We use the parks facilities a lot so we never have to dump the black tank during a stay.