[Carl n Susan]

I love my HD flexible "Y" splitter too. The water supply hose for the RV goes on one side and my gray hose goes on the other. The gray hose is predominantly used to flush the black tank although I have used it with a sprayer nozzle to rinse off garden tools and equipment.

I *HIGHLY* recommend you disconnect the hose from the black tank flush connector once you are done flushing the tanks. This relieves the pressure in the line but more importantly it avoids accidentally filling the black tank if (when) someone inadvertently (or on purpose) turns the water on to that side of the "Y". Over filling a black tank will ruin your day!