We’re often in some areas with very hard water, which leaves buildups on counters etc. So we recently purchased a portable water softener for our coach:

It came with water hardness test strips:

I connected it to our (already complicated) water system after the filter, to eliminate any impurities before softening the water (of course, I use quick-connect fittings, to make hooking up and disconnecting easier):

One more thing to get out and put away each time; one day I’d like to build both the filters and softener into the coach, but it doesn’t take long, and is worth it for better quality water in our coach.