Buying a Former Rental Class C. How many of us out there?

Update - I believe I was wrong. You should be able to empty your gray water tank without emptying your black water tank as they're operated by two separate release valves (Majestic 19G). They have one primary tube (?) that they both connect to for the (waste) water to come out of. So yes, you can open one value without the other (duh)...I just only ever emptied the black then the gray. I was apparently seeing tunnel vision : ) so pardon any confusion, sorry.