MrVan, before you get the hose, which I can't help you with, Check with the local LP dealer and make sure they will come out to fill a 100lb bottle. The reason I'm suggesting this is that the camp host here was using 2 100lbs and no one would service them on site. So he had to take the bottles to them to be filled. He ended up renting a 250 gal. tank from another LP dealer and they would service it on site. They also brought the hose and connected it to the trailer.
I think why they can't service then on you site is because they have to weigh the bottles to fill them.
