The only thing I hate about road tripping across the country to see my parents is washing my car when I get there. Their water comes from a well and is super hard. By the time I get back home, I almost have to re-correct my paint and put down some more sealant to make the paint smooth again. I use CQuartz on my car. I haven't tried any systems yet, but I've come across some basic resin filtration systems. One is an inline filter that attaches to the garden hose and is good for about 20 washes for $30. Another was a bag of resin that sat in a bucket and you ran the hose through it. I'm not looking to break the bank for those roll around dual filters for $400, I just want to wash my car there every once in awhile. Anyone have any tricks or come across something that's decent to use?