If you leave your unit connected all year, as we do, you won't have a problem with things growing in the water filter. It gets changed each year after de-winterizing, and the whole system gets sanitized prior to putting the new filter in.
We use the Redhawk a LOT during the year... staying in it during a power failure, using it as a guest house, grabbing a cold drink out of the fridge during yard work, and of course, camping, etc. So the water system get plenty of use.
Fortunately, where the filter is in the 26XD makes it easy to change... the 23XM filter was a bugger to change!
2016 Redhawk 26XD
Me, Dear Wife,
2 Bluetick Hounds
1 Newfoundland / Black Lab Mix
1 Cairn Terrier