[Chester Stone]

I'm confused. I would think a 1998 would be similar to my 2001. I have only one 160 gallon tank with two valves. The valve closest to the tank will retain the black water when closed up to 160 gallons, but the other valve has to be open to constantly divert the grey water into the sewer hose. I normally follow the practice of filling the fresh water tank at the same time I drain the grey/black water tank, and thus I never have be concerned with how much is in the sewer tank and both are always in balance.