We use the RV islands at the J, usually. If we park at a friend's house or an RV park, we'll take advantage of the situation and top the tank off before leaving. We buy
in-line water filters in the RV section of Walmart and change them often. No issues so far.
The real challenge is where to get water in the winter. Unless you run frequently in the deep south, you'll find all water spigots shut off to prevent freezing. You can sometimes sweet talk the maintenance guy at a truckstop to hook you up (deserves a tip) to a working spigot. I keep a
solar shower bag on hand and when water is scarce in the winter, I'll fill it with warm water in the ladies' room and take it back to the truck to do dishes or wash our hair. It doesn't take up much space and we have to resort to it quite often in the winter.