Water tank Fill from City Hookup
 

This is a thing I do to all my campers, 4 so far:
A valve so water can flow into the fresh tank from the city water hookup. No more holding a hose filling outside. Just turn the valve and let the tank fill. Excess flows out the gravity fill hose/tube, which I open during fill.

https://www.hilotrailerforum.com/mem...-fill-port.jpg
The red is PEX pipe. Flexible and moldable with heat, saves $ on elbows. Works on the same fittings. -I found it easier to attach if you heat the red pipe a little before slipping it on.

That's a great idea!