Flushing tanks

[JRS]

I’m not sure I understand how you are back flushing grey to black tank can you elaborate?

Turn on SaniCon(I like to do this to make sure it's working). Open blk tank valve and empty tank. Once empty, turn off the SaniCon. Keep blk tank valve open and open grey tank valve. Grey tank affluent will flush into blk tank. When you hear that the grey water is no longer going into the blk tank, close grey tank valve and turn on SaniCon to empty the blk tank. While keeping the SaniCon on and when blk tank is empty, close the blk tank valve then open the grey to finish emptying it.
When the grey tank is 80-85% plus full you can hear the grey water flushing into the black which helps keep it clean. Was taught this during Newmar Factory Pickup.

 

[NWIP]

Thanks for the explanation, never heard of that before but understand