Hard water is the number one cause of water spots. As tap water dries on paint, glass and coatings, it leaves behind the calcium, magnesium and other minerals dissolved in it. Those spots can etch into the surface if they sit. Deionized (DI) water has those minerals removed, so it dries clean.
Why detailers use DI water
- Spot-free final rinse. Rinse with DI water and let the car dry without chasing water spots, even in the sun.
- Less towel contact. Because it dries clean, you can do less drying, which means fewer chances to add swirls.
- Better chemical dilutions. Mixing soaps, quick detailers, sealants and coating maintenance products with DI water keeps them working the way they were designed to, without minerals interfering.
- Safer for coatings. Ceramic coatings are especially prone to water spotting. A DI rinse helps keep them slick and spot-free.
- Streak-free glass. Mix your glass cleaner with DI water for a cleaner, clearer finish.
How to use it
- Wash the car as usual. See our two-bucket wash guide.
- Do a final rinse with DI water, working from the top of the car down.
- Let it air dry or blow it dry, then lightly blot any remaining drips with a clean drying towel.
- Use DI water in your spray bottles any time a product calls for dilution.
Get DI water at our store
Pick up deionized water at Vital Detail Supplies, 9121 Garvey Ave, Rosemead, CA 91770 (Mon–Fri 8am–5pm, Sat 8am–4pm). Call us at (626) 656-6226 for current availability and pricing.
Already have water spots?
If minerals have already dried on, a dedicated water spot remover will break them down safely:
For mixing your dilutions, grab a CarPro Dilute bottle.