We have a 7-gallon, Reliance Aqua-Tainer (about $15) that I think we bought at Walmart. After fiddling with cut-off plastic bottles, funnels, etc., with little success, and most of the water on my pants, shoes and the ground instead of in the freshwater tank, I took the cap/spout (see below) to Ace Hardware and purchased some clear, heavy-duty plastic tubing (suitable for drinking water) that fits up inside the spigot. I got 6-8 feet, but the length you'll need is dependent on the distance between the water container and the freshwater fill port.
Cut a notch in one end of the plastic tubing to match the ON/OFF hole inside the rotating plastic valve portion of the spigot. Then, push the tubing fully up inside the spigot nozzle.
When properly installed, water should flow through the tubing when the "faucet" is turned ON.
We place the Aqua-Tainer on top of the propane tank cover, which is above the level of the freshwater fill port; so the water in the container drains by gravity. However, use care not to damage the propane cover; because 7-gallons of water are heavy.
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Reliance 7 Gallon Aqua-tainer, Aqua Tainer, Water Storage Containers | Campmor
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