According to the filter guy, it's necessary to keep the filters wet and actually in a "closed loop" condition when disconnected. I'm sure these are designed more for the stationary crowd. I probably went overkill on them but my wife really likes the significantly better taste of the water and frankly, so do I. Water quality varies so much when you're on the move as well. We've tried the throw away version from Culligan et al and this really is quite the cat's pajamas. I also have an adjustable water pressure regulator on it as part of the filtration array. The canisters unscrew from the top so they need to be suspended to some degree as well.
http://www.rvwaterfilterstore.com/WCStandardCanisters.htm