Water treatment options for a spotless car wash

For a spot-free rinse at the end of a car wash, the water treatment system you use is key. Read on for your car-friendly options.

These days, car wash customers not only want a sparkling clean car, but they also want it to be spot-free – and they’re willing to pay more for it. To keep up with customer demands, car wash owners are looking for inexpensive solutions to remove spots.

Using normal water for the final rinse leaves residue that forms spots because of the naturally occurring minerals in the water. To avoid these mineral deposits, it's important to have a spot-free rinse as the final step in a car wash.

There are two main technologies that can reduce dissolved materials in water, and spots on cars: Reverse Osmosis (RO) and De-Ionization (DI).

• A typical RO machine is relatively basic, making it cost-effective and easy to operate.
• RO technology does not use chemicals, which means it's a safe option.
• The equipment needed to add RO technology to a car wash is relatively simple – the owner just needs to install an RO machine and membranes.
• An RO machine could last 10 to 15 years since the only item needing attention and occasional replacement is the membrane element that removes material from the water. When maintained correctly, the membrane elements can last two to three years.
• Once the equipment is in place, the RO system uses the car wash’s standard water source (generally city water) as well as two common pretreatments — water softening and activated carbon.
• Since many customers will pay extra to have a spotless car, the system typically pays for itself in about a year, providing a fast return on the initial investment.
• The one key disadvantage of an RO system is water usage. The car wash is always generating a concentrate stream, which means owners will find that they use more water to create a spot-free rinse.

• The DI technology offers good quality but has a significant capacity limitation – the DI tank can only remove materials to a certain extent.
• Car wash owners have two choices with DI technology: regenerate on site, which is a meticulous process involving hazardous chemicals, or a tank exchange where a fresh tank is delivered when needed.
• Although the initial investment may be small with a tank exchange, over the course of a year, the cost of replacement tanks quickly adds up.
• Regenerating on-site involves the risk of dealing with hazardous chemicals, which is dangerous and not recommended for the typical car wash owner.
• Without the right mechanical skills and knowledge to properly use these chemicals, DI can be unsafe.