I too have been thinking about the lack of a gray tank. This may sound stupid (I'm not exactly a stranger to that concept) but here goes ...... Is there not some way to use a "Y" to hook the gray water into the black water disposal line (refered to as the "poop shoot" around here) and into the sewer? Or maybe a "Y" at the sewer and two lines into that ? If you use a bucket or port-a-tank where would you dispose of that?