In today’s automated carwash tunnels and bays, there are dozens of factors that can negatively affect wash results and customer satisfaction. Consequently, the savviest carwash owners and managers follow a strict schedule of daily test cycles and equipment maintenance. These monitoring steps are especially important for one of the most widely blamed culprits when it comes to poor cleaning results in a carwash: water quality.

Water is widely recognized as the lifeblood of both modern carwashes and their installed equipment. Water is called upon during every wash phase, including all presoak steps, foam applications, wash cycles and multiple rinse phases. As such, a wash with poor water quality will see limited results via multiple phases of operation.

Thankfully, there are updated processes for properly measuring and then treating the water coming into a carwash. By following a series of recognized steps, an operator can ultimately perfect the water quality for all wash and rinse cycles. From initial water testing to installing treatment equipment, find out what best practices water treatment experts recommend for today’s active carwash businesses.

Water quality and results

Regardless of the equipment an operator is using, water quality will have a huge impact on a car care business, according to Mike Jorgensen, sales manager with Autowash Systems Inc. Steps should be taken to ensure an owner is using the correct type of water in the different phases of his or her wash operation. Jorgensen’s initial suggestion is to get in touch with a local equipment distributor to evaluate a site’s specific needs.

Generally speaking, different types of water require different types of treatment. “Hard water or untreated water can cause a lack of efficiency in chemistry and rinsing applications,” Jorgensen explains. “Most washes use a combination of water types to reach their desired outcome.”

What exactly is hard water? “Hard water is often considered anything higher than four grains of hardness per gallon (gpg), or 70 parts per million (ppm),” Jorgensen says. As stated, hard water does not work well with chemicals, and if used on a final rinse, it will often leave spots on a vehicle after drying.

Comparatively, soft water provides a better foaming profile and allows presoaks to fight the dirt on customers’ vehicles more effectively. Jorgensen states that the cleaning chemicals are often more effective when they are not also battling minerals in the water. Thus, an operator may actually save money on chemicals when he or she utilizes treated water during application. An operator can also expect to see a better show from foaming agents when using softer water.

But, soft water is not only great for chemical applications. Many washes also feed their reverse osmosis (RO) systems soft water to produce spot-free rinse water. “Feeding an RO production unit with hard water is not recommended, as it will shorten the lifespan of the membranes used for filtration,” Jorgensen warns. “If one is on a city water source, I would highly recommend a carbon filter to knock out any chlorine that may be in the water. Chlorine is problematic for RO membranes.”

As the RO system is fed treated soft water, it will further filter the water to remove any additional or residual hardness in the water, according to Jorgensen. This leaves water that is virtually free of all minerals, and after drying, it leaves a spot-free vehicle surface. But, owners should remember that these systems typically are only about 50 percent effective. This means that half the water going in will be waste water.

“If one’s water treatment systems — reclaim, softener, reverse osmosis, etc. — are not functioning correctly, the wash may have difficulties producing a great final product,” Jorgensen notes.

Needed equipment

Lee Bonin with SoBrite Technologies notes that today’s modern express washes will often include water softeners and carbon filters. This equipment removes the hardness and chlorine from provided city water. Bonin agrees that this water can then be fed to the RO or spot-free unit for the tunnel’s final rinse. Here, the water softener and carbon filter treatments are important for prolonging the membrane life of an RO unit.

Water reclaim systems are massively important, as they clean the used carwash water to a point where it can be reused in the wash, according to Bonin. Another piece of important water treatment equipment would be a concentrate/reject capture system. The water saved here can be used in different areas of the wash instead of going directly down the drain.

“The two systems I mentioned, reclaim and concentrate/reject capture, not only save money for the carwash owner via water bills, but they are also very good for the environment, as they are decreasing your fresh water consumption,” Bonin states.

Jorgensen further explains the popularity of water reclaim systems: “By means of capturing, settling, treating and reusing wastewater from a wash, an operator can save significant utility dollars.” Also, if a municipality requires water access charge (WAC) or sewer access charge (SAC) fees, they may be lessened because of the decrease in wasted water. Even if a total water reclaim system does not make fiscal sense for an operator, Jorgensen would still encourage building in a system to capture and reuse the rejected water from the RO production unit.

Reclaimed water is great for underbody and high-pressure applications, but it should not be used for chemical applications and rinsing, Jorgensen continues. Finally, not using an RO rinse water could be problematic depending on the overall quality of the municipal water supply as well.

“Again, I would suggest harnessing waste or reject water and using this in other areas of one’s wash, perhaps in an undercarriage application or prep gun,” Jorgensen says.

Bonin reminds operators that there are different stages of rinsing in a tunnel carwash and points out that all rinse water does not have to be treated. Only the final rinse should be the spot-free rinse. If a wash is regularly experiencing spotting after the final rinse, the first step should be to check and see if the RO or spot-free unit is working properly.

Best practices

When it comes to water quality best practices, Jorgensen lists the following:

  • Monitor total dissolved solids (TDS) and water hardness levels routinely.
  • If a wash is utilizing a water softener system, an owner or manager must keep the tank filled to the appropriate level with salt.
  • Most water reclaim systems will require some level of filter maintenance; it’s important to follow the manufacturer’s recommendations.
  • Pay attention to the final product.

Bonin explains that with water quality equipment, maintenance is key. Maintenance is vitally important to help the equipment put out a clean, dry and quality exit vehicle.

Properly measuring water usage is another important best practice. As with other utilities, one way to ensure against a surprise, skyrocketing usage cost is to closely monitor the amount of a resource that is used. Monitoring will prevent surprises due to equipment issues or other problems with utility service.

Jorgensen states that most equipment manufacturers have specific usage rates for each application. An operator can also look into purchasing a metering system to monitor a location’s actual water usage.

Nozzle replacement is another important factor in measuring water usage. “Your water use is determined by the type of equipment you are using in your tunnel,” Bonin says. “It is based off of the gallons per minute of the nozzles being used to discharge water from the tunnel equipment. The gallons per minute is based off of using new nozzles as well as the size and quantity of nozzles being used on your tunnel equipment. So, it is very important to change your nozzles regularly to keep your water usage at the desired gallons per minute.”

Testing procedures

Jorgensen notes that water TDS or hardness meters are widely available, and they should be called upon routinely by carwash operators to monitor RO membrane effectiveness. “After a period of time, the filters or membranes in the RO systems will need to be replaced when they become saturated with materials,” Jorgensen says. Keeping an eye on the TDS levels will help an owner identify when it is time to change out a membrane. Today, many RO production units actually have the meter built into the system itself.

In addition, a local carwash distributor will be able to help an operator with water quality testing, according to Jorgensen. Otherwise, TDS kits are widely available and fairly easy to use and, ultimately, understand.

Bonin reveals that there are actually multiple water quality tests that can be done at a carwash. An owner can test TDS, the pH level in the water, iron content and chlorine levels. These tests will help an operator determine the type of water treatment equipment that is needed.

“Test kits can be ordered through water treatment solution companies, online or at your local pool supply company,” Bonin concludes. “Once you have tested your water and recorded the results, you can consult with your water treatment solutions company for their recommendation on how to proceed.”


Michael Rose is a freelance contributor.