This is really embarrassing. We always filter our water from the outside. Being full-timers, we change it quite often as we do travel quite a bit. Many of you have the filters inside your coach or rig, often under the sink, and almost always a second one in the fridge if you have the luxury of a built-in ice maker. (I don't, but I did buy a portable one for Mike for Christmas two years ago which he loves.)
Even with the filter, hard water sediment will still build up. You can't camp in as many places as we do and not collect it. Every two months or so, when the shower water pressure slows down, I remove the shower head and hose and soak them in vinegar for about 15 minutes. I then blow air through one end, emptying the trapped water in a clear jar to see how much sediment is still present. I repeat the steps til I'm satisfied, rinse them out well with clear water and replace them.
(Note: In air conditioning weather I also wash out my filters at the same time - both ac and my vent filters. In sandy states, like Florida, they get filled quickly).
Fortunately, I'm working part time for Thousand Trails in Camping World. I am supposed to know where things are, and periodically wander through looking for ideas (a dangerous move, trust me!). Two weeks ago I spotted a gizmo for flushing out the hot water tank easily. The water at this campground is so hard, that my vinegar treatment and filter-changing were not effectively helping with the shower pressure. It was time to do something. Several times I saw other RVers purchasing the Tank Saver RV Water Heater Tank Flushing Tool, so I knew we weren't the only ones having issues.
The packaging says it takes about 10 minutes, twice a year to keep your tank running smoothly . . . but that doesn't apply if you haven't drained it in three years, since it left the factory!!!! It took several (embarrassing) flushes, but what a difference. And easy? I can do it alone easily. Atwood hot water tanks have no anodes, but even those that do will follow the same procedure. The directions are easy to follow.
You can be sure we won't let that happen again! Happy Camping, everyone.