Might sound crazy, but I use a few gallons of bottled water. Either grocery store brand for .50, or a deep rock well water station .35 per gallon. Both waters ...

Might sound crazy, but I use a few gallons of bottled water. Either grocery store brand for .50, or a deep rock well water station .35 per gallon. Both waters are very low in overall mineral content, and that is what is causing the spots. I'll do a full hose rinse first, then simply douse the "cleaner" water from the top down. It doesn't take much to wash away the "bad" water. I'm not trying to soak the whole truck, just enough to wash away or dilute the tap water. Then I will still go ahead and dry the truck, either with my $30 Toro leaf blower, or with a microfiber towel.

If I am doing a full detail, I will use the blower to make sure I have all water gone. Water running down from a crack onto a polish or wax pad isn't good. But once I get the initial full detail and proper paint protection, most water just runs off on it's own, no need for a special rinse system or water. I'll still use the blower if needed, or just a towel carefully to avoid scratching. Any spots left over are removed with a clean towel and a spritz of quick detailer spray.

CT2500HD wrote:You can just use a cheap $20 carbon filter inline with your hose. It will limit pressure, but if using a pressure washer they don't need much input pressure anyway.

https://www.amazon.com/gp/product/B01D57CVEM/

a carbon filter will NOT achieve the same result as a mixed bed deionizing resin filter like the op posted.

apples vs bananna's. carbon is often used (in drinking water applications, etc) as a pre-filter for more advanced filters (like reverse osmosis or deionizers like shown) to remove heavy metals to save a little bit of resin life, but you'll never get the dissovled carbonates and such that are leaving behind the hard water stains that the DI cartridge will do. activated carbon's primary purpose beyond heavy metals (mercury, lead, copper (very very limited uptake capacity here), and some chemicals like chlorine, etc - is to improve flavor and pickup large particles as they're usually 5-10 micron passthrough.. it's pretty much uselsss for anything else including but not limited to iron removal, etc etc etc.


to the OP: DI resin cartridges like this are great at first, but the more you use them the less effective they are until they're worn out. the worse your water is going in, the faster they will fail. As noted replacement cost is pretty high as well. you can save a few $ by going to a refillable cartridge in that housing, but you're gonna pay somewhere on the rate of $8/lb unless you're willing to buy in serious bulk (50ish lb) and then you can about half that rate.

https://www.amazon.com/Aquatic-Life-Mix ... 01HT4CMP0/

https://www.amazon.com/Mixed-Exchange-S ... 007IW0HNS/

you'll be better served ( long term if you dont have one already ) to work with a trusted local water treatment company, get a water analysis done and install a proper whole house water treatment & softener system. if you have a lot of rust stains, adding an iron filter in front of your softner is going to run you another few hundred more $, but the added expense will extend the life and efficiency of your softener out by a measure of years and will absolutely pay for itself long term. its not cheap, but its defiantly worth it in the long run, especailly when you're talking about getting a >$200 product just as a bandaid to wash your ride with.

then talk to a plumber about hooking in a bypass so that you can run - as needed, just by turning a couple valves - softened water to the outside spigot(s) that you use for your car washing. Outdoor spigots are pre-softener as the salt they use can play hell on certain (most) species of trees and other plants in your landscaping if you're irrigating with it. plus you'll burn through way more salt if you're watering on the regular so there's a cost issue too.

that'll probably be a more effective long term use of your $$ than trying some bolt-on inline system like the link you've shared.

hth