'help' is a universal cry here...
welcome to the forums.
navigate the forum table of contents page and u will see a LARGE variety of SUBforum headings...
for example 'fresh water stuff' goes here...
Plumbing - Systems & Fixtures - Airstream Forums
maybe the mods will move yer post,
2 da plumbing/freshwater section...mehbe
don't sweat it.
white hoses are almost universally FRESH water hoses in rv land.
the 4-ft hose is supplied so u can connect it TO the fresh water INPUT...
the run the hose into the white box and OUT THE BOTTOM via the plastic portal/slider door...
have u seen that?
then one can attach the MAIN freshwater hose or water filter to that short section while in use.
i leave the short white hose connected 4 ever, and push it back into the hatch when not connected to shore water.
a hose/CAP screws onto the open end to keep out critters.
not everyone does takes this approach but that IS the purpose of the short hose.
i don't use the factory/oem BTF but here's a bit of info on using it...