So this is what I did to eliminate having to switch a hose back and forth and perhaps increase the water volume due to the downsizing of the valve. I just used it last trip and it worked amazing. However, I am sure many would be concerned with the black tank aspect of this setup. So I throw this out for all to throw in their thoughts in the ring as to why this may be a bad idea. I can always add a check valve on to the Black tank side. Since the black tank lines are not pressurized, I felt as though the valves at the manifold are good enough, as long as I close the fresh water side when flushing black tank. You may not see it, but I have a flow meter at the hose connection. The hoses are for a hot & Cold water connection for a washing machine.