why separate tanks for grey and black water?

jplante4 wrote:

dave17352 wrote:
I actually explained what I do wrong. I leave the cap on the sewer outlet and open both the black and grey valve.

I did it this way...once. Then I realized that I had a mixture of black and grey water between the valves and the cap that had no place to go except into the waste bay. Holding the hose above tank level accomplishes the same thing with no mess.

My outlet is outside. I simply close the valves and open the little hose cap and drain what little is in the line into the hose then connect the hose and drain. No problem at all for me. I know some people simply hook a valve right to the end of there dump valve accomplishing the same thing.