What is 0ppm Pure Water Washing and Why Does It Matter?

If you've ever had your car washed and noticed water spots appearing as it dried, you've seen the effect of tap water on paintwork. At Juicy Car Care, we use 0ppm pure water for every exterior wash — and here's why it makes a real difference to the finish.

What Does 0ppm Mean?

PPM stands for parts per million. It's a measure of how many dissolved solids — minerals, salts, and other compounds — are present in water. Tap water in the UK typically reads anywhere from 100 to 400ppm depending on the area. In parts of West Sussex, it can be even higher due to the chalky geology of the South Downs.

0ppm water has had all of those dissolved solids removed through a process called reverse osmosis, combined with de-ionisation. The result is water in its purest form — with nothing else in it whatsoever.

Why Does It Matter for Car Washing?

When ordinary tap water evaporates off a car's paintwork or glass, the water disappears — but everything dissolved in it is left behind. Those mineral deposits form the white, chalky spots you see on dark cars after washing, especially in direct sunlight or warm weather.

These water spots aren't just cosmetic. On glass, they're notoriously difficult to remove and can etch into the surface over time if not addressed. On paintwork, particularly on cars with a ceramic coating, they can bond to the surface and require specialist removal.

0ppm pure water contains no dissolved solids, so when it evaporates, nothing is left behind. The car dries completely clean — no spots, no marks, no residue.

The Difference on Glass

The most noticeable benefit of pure water washing is on the glass. Windscreens and windows that are washed with tap water regularly build up a thin film of mineral deposits over time. This creates a hazy, smeared appearance — particularly noticeable when driving into low sun — and reduces visibility.

Washing with 0ppm water prevents this build-up entirely. Existing mineral deposits can be removed with the right treatment, and pure water rinsing keeps the glass crystal clear between washes.

How We Use Pure Water

Our mobile setup includes an on-board pure water system. We pre-rinse the car with pure water to loosen surface contamination, wash using the two-bucket method with pH-neutral shampoo, and then give a final rinse with pure water. That final rinse is what allows the car to dry without any water spots forming — even if you don't dry it by hand straight away.

This is particularly important on ceramic-coated cars, where a spot-free rinse is essential to preserving the hydrophobic properties of the coating.

Does It Really Make a Visible Difference?

Yes — especially on darker coloured cars. A black or dark grey car washed with tap water and left to air dry will almost always show water spots. The same car rinsed with 0ppm water will dry virtually mark-free.

It's also the reason professional detailers and car show enthusiasts use pure water as standard. When you're presenting a car or protecting a high-end finish, water spots simply aren't acceptable.

Book a Professional Mobile Wash in Worthing

Every exterior wash we carry out uses 0ppm pure water as standard — it's not an add-on. If you want your car washed properly, without the risk of water spotting, give Jay a call on 07739 918403 or email info@juicycarcare.co.uk. We cover Worthing, Lancing, Shoreham, Hove, Brighton, Chichester, and the surrounding areas of West Sussex.