We usually head out on a trip with the potable tank full. We're very lucky that Anacortes has some of the best quality water in the country. We usually hook up at the CG, and we use the city water for everything except drinking (us and the dogs) and cooking.
The rig was new to us last July, so I haven't had a chance to add a solenoid valve to the city inlet yet. Until I do, we just go outside and shut the city water off to use our on-board supply.
Frank and Eileen
No longer RVers or FR owners