Ok guys, I thought I would do a little write up on this little set-up. I've had it for a while, but it's been at my friends house and he gave it back to me a few days ago.
This is the product... Garden Hose Filters – Pure Water Products, LLC
I have the double filter set-up just because I wanted the extra insurance of having better filtration, but a single filter will do. The double filter set-up is about 50.00 if you get in white. I bought it in clear blue which was 55.00. The resin cartridges are 19.00 each, a short hose will run you 8-12.00 and a bag of softener salt will run you 4-5.00 for I think 40 lbs from lowes.
It's all very easy to set up and I ran into no issues.
I went ahead and did my normal wash but if you have hard water like I do, the first think you notice is that the water just feels more slick (I guess from less minerals being present), you get more suds as well. The sponge slides over the paint better vs. before where you could just feel more friction on the paint. Rinsing the car you also notice the water falls of differently and with what seems to be less effort.
The real test for me was going to be the drying. I plugged the leaf blower in and start drying. The water, again, came off much more effortlessly, it didn't seem like that there was as much friction. Even when using the blower on the roof, it's so much better.
After the car was dry, there were obviously less spots... no serious spots though.. nothing that couldn't be easily removed like the pre-filtered water that would leave embedded spots all over the glass.
The filters only need to be recharged by putting some of the salt into the bottom of the pain and adding enough water to cover them, so they don't need to be replaced like the better, but MUCH more expensive deionizing systems that have to have new filters bought pretty frequently, and they aren't cheap.
IMO if you have water, this is a very good investment whole set-up being pretty inexpensive.