gray water tank

I had a similar issue with mine. When I complained to my dealer when it was still under warranty, they checked it out for me. It turned out that the tank is a bit of a wedge shape, with the back side of it a couple of inches shorter than the side where it drains out. They shimmed up the back side a couple of inches with a block of styrofoam so that it would drain out more completely when dumping, and so that the top of the tank was more level, instead of the bottom, creating more usable space (depends on where your shower drain is). They also suggested using the leveling jacks to lean it toward the dump station, which I do now.