We use a clear insert piece similar to the one found here: (our doesn't have a bend in it though)
http://www.campingworld.com/browse/s...e/skunum=14496
(may have to cut and paste since it is too long to show up as a link and I am too lazy to go to tiny url's to get a small one.
The valve the water hose attaches to is a 3 way (off, tank, hose). We attached a quick connect fitting to it so I can quickly remove the hose from you water filter (hooked inline to my TM city water connection) and attach to this connector to rinse everything while connected.
Bill