why separate tanks for grey and black water?

Dutch_12078 wrote:

jplante4 wrote:

dave17352 wrote:
I agree with all the posters here. Now on occasion I have equalized my tanks when I need more grey water room by opening the grey valve and leaving the black tank valve closed. This brings them to the same level.

I don't see how this equalizes the level. If you were to open both valves and hold the stinky slinky above the top of the tanks, then the fullest tank would sluice into the emptiest tank. Hopefully, the grey tank is fullest.:E

I do this to provide a little extra liquid to flush out the black tank. Be sure to hole the hose high.

I added a third "Main" valve to my dump setup. To equalize the tanks, I just leave it closed while opening the grey and black valves. When dumping, I open the black and main valves, and when the black tank is empty, give it a quick rinse by closing the main valve and opening the grey valve for a couple of minutes before opening the main valve again to drain the grey water.

I actually explained what I do wrong. I leave the cap on the sewer outlet and open both the black and grey valve. Both of my tanks are mounted at the same level in my TC holding area. With both valves open the tanks equalize. Like I said if doing this I know I will not have have sewer water in the shower because I know both holding tanks can hold the entire 46 gallon fresh tanks contents. I checked this to make sure before doing this. Works great if needed. But usually this is not necessary but when it is it works great.