Total Dissolved Solids: The Ultimate Guide For Aquatic Operators

Do you ever wonder why your pool water may begin to look dull and not as sparkly as it once did? It might be due to your total dissolved solids. 

One of the most overlooked concepts in pool water chemistry is the measure of total dissolved solids. Your total dissolved solids, or TDS, value is the measure of the sum of all the substances dissolved in your pool water. Freshwater swimming pools should have a maximum TDS value of around 1,500 to 2,000 ppm. For example, drinking water can have a maximum TDS value of 500 ppm according to the EPA. TDS meters are readily available and can be purchased online at very reasonable prices. 

The TDS Problem

Virtually everything that is added to the pool contributes to an increase in the TDS value including chlorine, shock, algaecides, clarifiers, pH remediation products, etc. Even bather-introduced contaminants such as hair care products, body lotions, deodorants, sweat, urine, etc. can significantly add to TDS levels. Another TDS concern for outdoor facilities includes any lawn care or landscaping chemicals that may inadvertently find their way into the pool. Evaporation of pure water from pools can also leave behind a higher concentration of TDS over time.

Chlorides and sulfates as TDS in your pool can cause problems such as reducing chlorine efficacy, dulling pool water clarity and allowing algae to bloom. High levels of phosphates and nitrates can consume chlorine and also help algae bloom.

High TDS Indications

If you repeatedly have problems maintaining the proper chlorine levels, water clarity or your pool water has a salty flavor – even though the water is properly balanced, sanitized and filtered – you might have a problem with TDS. High TDS as a result of dissolved metals can also result in staining of pool surfaces. 

High calcium-based TDS can result in scaling, both on pool surfaces and in pump room equipment, which can shorten the service life and lead to costly repairs. As TDS levels begin to exceed the 2,000 ppm range, the risk of galvanic corrosion also increases due to the concentration of dissimilar metals within the system.

The TDS Solution

Conventional swimming pool wisdom tells us that the only way to reduce TDS is through drain-and-filling which, to an extent, is true. However, there are other methods that are able to remove large amounts of TDS in water such as reverse osmosis and micro-filtration using membrane filters. While these methods are preferred over the water-replacement method in some areas of the country due to water restrictions, they are very costly and time-consuming and they still result in a high volume of wastewater. 

The Clear Comfort AOP Approach to TDS

The Clear Comfort Advanced Oxidation (AOP) pool treatment system has proven to be effective at removing some of the total dissolved solid metals found in pool water via precipitation through oxidation, including iron and manganese, which also contribute to staining. These metals, however, only represent a fraction of the significant TDS found in swimming pools.  

More commonly, ions such as chloride and sodium have the biggest impact on a TDS value.  While Clear Comfort AOP has not proven effective in removing chloride and sodium ion TDS from primary sanitizers, it can reduce the need for these chemical sanitizers by 40 percent on average. Therefore, reducing the amount of chemical sanitizer required to clean the pool can result in fewer TDS added to the water and, in turn, reduce the frequency of water exchanges. 

In addition to reducing chlorine consumption, Clear Comfort AOP pool treatment allows aquatics facilities to reduce disinfection by-products, improve air and water quality, eliminate pathogens from the pool water, consume less energy and reduce time spent on maintenance. As top facilities continue to implement modern solutions, like Clear Comfort AOP, commercial pool water care has become more stable, simpler and safer than ever before.

 

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With a Bachelor of Science in Biology and Chemistry from Metro State University of Denver and an MBA from Grand Canyon University, Zach is excited to join the Clear Comfort team and expand his extensive career in commercial aquatics. Zach holds 15 years of experience as a commercial swimming pool operator and has owned a pool company, which specialized in repair, maintenance and training. In addition, Zach has been a CPO instructor for the National Swimming Pool Foundation since 2011. Zach is a Colorado native who loves to travel, run marathons, scuba dive and spend time with his wife and two boys.