RV Expert Center
Extra bladder makes refilling an RV water tank simple
These containers make it possible to refill your RV's fresh water tank without taking it to a water station. According to RVBoondockingNews.com, these bladders are especially useful for boondockers and those without access to refill fresh water tanks.
Here's how it works: the bladder is filled and strapped to the top of a tow vehicle. When it is driven back to the RV, a water hose connects it to the RV water inlet and gravity helps transfer it. Some people opt to use an RV water pump to transfer the water if they can't or don't want to use the roof of a vehicle to carry the bladder, since it can dent the roof of a car or SUV when filled.
A 45-gallon portable RV fresh water tank retails for less than $90. Some commentators on Camping World say it's a great option for camping without hook-ups if you have the time to transfer the water, which can take about an hour.