Do you have a project car? Maybe a weekend driver, a special sports car or a cherished car? As car guys or gals there are always special ways to keep your prized possession clean. Even if you don’t have a hot-rod or classic car, you may want your daily driver Looking the best it can. However, sometimes the quality of your water may end up leaving spots on your paint and trim. What can cause that?
Hard Water
Here in North Carolina you can have “hard” water, we’re referring to water that has a lot of calcium and magnesium. A typical treatment for hard water is called “Softening”. This is the process of treating the water and swapping those minerals for sodium or potassium.
Car washing with hard water can be the cause of the aforementioned water spots, but that’s not always true.
Fun Fact: Did you know that the first car wash was opened in 1914 in Detroit? It was called “Automated Laundry” and cars were pushed through a tunnel by workers while being cleaned by hand!

Hard water is just one part of the story. The real issue is the total amount of minerals in the water, known as TDS (Total Dissolved Solids). The higher the TDS, the more spots you’ll get.
Softening water doesn’t actually remove minerals. It just swaps calcium and magnesium for sodium. So, the TDS level stays the same. Soft water has less calcium but more sodium. While soft water is easier to work with and doesn’t cause scaling, high TDS water will still leave spots, whether it’s softened or not. The good news is that these spots are easier to wipe off with soft water.
Spots happen because water evaporates and leaves minerals behind. The best water for washing your car is low TDS water. Removing all minerals is usually not practical for home users because it’s expensive. Professional car washes often use reverse osmosis water, which reduces TDS by about 95% and ensures a spot-free rinse.
Depending on your situation we may have a couple of solutions. Whether you have a Lamborghini or a Ford Pickup– if you want a car or truck that looks showroom clean we can help you out with that.
Steps to the perfect Water for Car Washing
- Setup an appointment – we will come out and test your water. Do a general Assessment and come up with a solution to meet your needs.
- We may recommend: Adding a water filter to the supply line that you wash your car with. A recommendation of a carbon filter is an easy next step.
- We may recommend: a water softener and an additional filter near the supply line could be a great addition.
- Depending on your setup, you may want to have 2 lines for the supply to the faucet. 1 to bypass with no filtering (using it in the yard) and 1 for filtered water for cleaning your car. It will help your filter to last longer overall.
Final thoughts: Using soft water can help you use less soap and make it easier to wipe away spots. If you don’t know the hardness or TDS level of your water, just give us a call, we will be more than glad to come out and do a test for you. Having cleaner water for your car is easily done and you will have a spotless car in no time.