Marv

I've looked at CR Systems and Water Stick. Does anyone have any experience with this product for rinsing their car?

Clear Rinse Syetm

My city water seems moderately free of minerals, but I live in Florida near the coast and need to wash frequently to keep salt spray off the car. A spot free rinse would make that job a lot easier!

Bruce SEA 993

I have a "whole house" filter from Home Depot that removes the minerals that cause water spotting. I have to get another one as it froze here and I forgot to drain it and it cracked. It is $35 or so and easy to install.

Ignore my ugly hose...

autobonrun

Depending on the amount of minerals in your water a single DI unit would work pretty hard and may have to be replinished frequently. Because I have a salt water aquarium, I tapped into my water line inside the house and installed a RO/Filter followed by the DI to produce makeup water for the aquarium. My water supply is about 350ppm total dissolved solids (TDS). The RO/filter reduces this to about 20 ppm. The DI then gets it down to about 2ppm. I think a filter/RO upstream of the DI would help get your TDS down to very low levels.

I store some of this water in containers and this is what I use for rinsing my car as well. It greatly reduces water spotting.

Marv

I am not sure how to convert mg/L to ppm, but my water is about 300 mg/L, which is very hard. The limit for human consumption is about 1600 mg/L.

It sounds like there is a lot of work to do to get the water down to a very low TDS level, so you are probably right. This will get expensive.

993c2cab

I also had the home depot one pictured in the previous post. It didn't work well still had spots, I had some pretty hard well water though.