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Testing for quality

Know what’s lurking in the water.


Rich DiPaolo is the Associate Publisher – Editorial of Professional Carwashing & Detailing magazine.

Today’s handheld analytical testing devices and test strips have advanced and more owners and operators, with the guidance of their local carwash distributors, are testing their water quality in-house. Water hardness, TDS, chlorine, which can damage reverse osmosis (RO) membranes and hinder carwash chemical chemistry, and pH can all be tested in the field with ease. While lab testing may be able to achieve greater accuracy and provide comprehensive results, there are practical reasons to field test.

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“There are some simple tests that can and should be performed in the field like pH. The pH of the water can fluctuate greatly over time depending on the makeup of the water, so this is a test that is most accurate when performed in the field,” says Marianne Metzger, director of business development for National Testing Laboratories. “Additionally, there are simple tests like conductivity/TDS, which are easy to run and can indicate when there is a significant change in water quality. Hardness is another simple test that can be performed in the field and is a useful measurement when you have spotting problems or are considering water treatment.”


Andrew Landa, director of research and development for Zep Vehicle Care, breaks down how to test for these common carwash water contaminants and conditions:

  • Water hardness should be tested using a hardness kit since increased hardness reduces detergent cleaning efficiency.
  • Dissolved solids should be tested with a TDS meter since increased levels of dissolved solids can produce post-wash spotting, streaking, staining or drying issues.
  • Test pH with a pH strip since pH variations signal a possible change in water quality which requires further investigation.

“Routine water quality monitoring and testing can be performed by wash operators,” continues Landa, adding that it is critically important to properly calibrate any measuring device prior to each use. “When water quality issues are present that cause heavy spotting, streaking or staining, resulting in a poor wash performance, it is recommended that the operator consult with water quality experts.”


Because water quality can change as a result of several factors, Hirsh recommends testing for pH, chlorine, iron, hardness and TDS in the field as a part of owners’ and operators’ monthly preventative maintenance programs.

“However, there are some contaminants that the typical [field] test equipment will not identify, such as orthophosphate, which can ‘blind’ the pores of an RO membrane,” asserts Gary Hirsh, president of New Wave Industries Ltd. “If the operator experiences a significant change in wash quality and/or if he or she notices premature degradation of the inline water treatment, I would definitely recommend sampling and sending to a local lab.”


Certified laboratories are best suited to perform and understand water tests since they are required to have quality control and assurance measures in place that ensure results are most accurate, reminds Metzger. “For those considering water treatment [for the first time], using a professional laboratory would be recommended,” she adds.

Testing water is an important first step and ongoing practice carwash owners and operators must add into their business routines. Without taking these considerations into account, curing your problem water can prove to be tricky. Partner with your local water municipality, speak with local businesses, including water treatment dealerships, and closely monitor your water quality in order to provide the best carwash possible.


You can read more on water contaminants and best practices for testing here.

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Professional Carwashing & Detailing