<VV> Off Topic - Hard Water Car Washing Solutions

[WADE LANNING]

I'm not familiar with the specific deionization system you refer to.  Hard water typically means it has high calcium and magnesium concentration.  These can be removed with ion exchange resin to soften the water.  The resin in turn has to be re-generated periodically with a salt (sodium chloride) solution.  Make sure what you buy is going to solve your problem.  There are companies that specialize in residential water softener systems.  You may want to read up on the topic, then talk to a few companies to see what they offer.  Here's a link with basic info:

https://www.thoughtco.com/chemistry-of-hard-and-soft-water-602182

Real soft water has drawbacks too, such as attacking copper, brass and even galvanized well pressure tanks if you have those in your plumbing.  Most new houses with well water have bladder tanks lined with rubber and plastic piping, but if there are brass elbows & tees in those systems, soft water will corrode those over time.  This is typically the cause of blue stains on white sinks from the copper corrosion.  There are also simple tests kits that check the water hardness level. 

Wade Lanning