Thanks so much....I seem to remember this video thanks for dredging it up from the memory hole. I get chance to meet some Thor owners at rally in a few weeks and hopefully they help me think it through. My worry is my gray tank rides above the black so I might just end up filling my black with gray water. The gray tank is about 4 inches deep and most likely 4x5 feet long and wide. The black is like a aquarium tank that is mostly below the the gray.
Fun to think about .. thanks again.