Evaluation of Water Conditioning Devices for Pool and Spa Applications
By David Nance
In order to meet market demand, NSF has developed a testing protocol to evaluate various technologies employed as water conditioning devices in pools and spas. This protocol is described in NSF’s Component Certification Specification (CCS), CCS-18325: Water Conditioning Devices for Recreational Water Facilities.
A CCS is a certification guidance document created for materials, components and products that fall within the scope of NSF/ANSI 50, but for which no specific requirements are currently provided. The typical lifespan of a CCS is short, as the testing protocols and evaluation criteria covered by CCS are typically incorporated into NSF/ANSI 50 Equipment and Chemicals for Swimming Pools, Spas, Hot Tubs and Other Recreational Water Facilities within two years from the date when certifications to the CCS are first authorized. Using CCS-18325 as their baseline, the Water Conditioning Device Task Group for NSF/ANSI 50 has worked hard over the last two years to establish a testing protocol and evaluation criteria for water conditioning devices.
Water conditioning devices defined
For the purposes of NSF/ANSI 50 and the work being done by the Water Conditioning Device Task Group, a water conditioning device (WCD) is considered to be any technology or device that, without the use of chemicals, improves the water quality in a pool or spa. Claims of secondary or supplemental disinfection are not covered by the scope of the CCS. A number of technologies and products currently in the market fall within this scope, plus there is the potential for new and innovative technologies and products that could be included in this scope in the future.
Keeping this scope in mind, the test protocol currently drafted by the task group includes guidelines for validating the performance of any product with claims regarding the improvement of the following recreational water quality parameters:
- Combined chlorine level
- Chlorine consumption for sanitizer level control
- Acid consumption for pH control
- Phosphate level
- Consumption of water required for circulation system filter cleaning
These evaluations have been developed to establish scientifically valid test results useful for end users to allow confidence and trust in product performance claims, such that they can then pursue the benefits these WCDs offer in terms of lower chemical costs, improved water quality and swimmer comfort, and reduced environmental impact.
Both safety and efficacy of WCDs have been considered as the test methodology for the CCS and subsequently NSF/ANSI 50 have been developed. Safety is evaluated through pressure testing, as well as including requirements for product installation and user information, including warning labels and mechanisms to protect swimmers and operators. Information regarding safety of the water conditioning devices allows facility operators to make informed decisions about product safety, reducing the potential for negative outcomes associated with WCD usage.
Efficacy of WCDs is evaluated in the laboratory, through controlled simulations of real-world conditions. To start the testing, a large volume of clean water is chemically balanced and filtered to obtain standard pool-water conditions. The WCD is then installed and the test water is circulated in a manner mimicking a swimming pool over a minimum period of one week of usage. During the test period, a particulate contaminant load and a synthetic bather load are dosed into the water at regular prescribed intervals. The contaminant load and bather load are intended to simulate the dirt, oils and bodily fluids that typically enter pool water from swimmers under conditions of normal usage.
The test method includes the use of automatic controllers, which monitor and adjust the water to achieve typical pool-water chemistry during the test period. The controllers also measure the amount of chemicals required to keep the water within specifications and the total water volume needed to clean the filtration system. This information is collected and utilized to establish the baseline for water quality and chemical and water consumption. This baseline is then used for comparisons to assess the efficacy of the WCD being tested.
After the baseline is established during a one-week period, the WCD is installed and operated according to manufacturer’s instructions. The baseline conditions are then repeated with the WCD in place and operating with the same data relating to water quality, chemical consumption and water consumption collected by the automatic controllers. The information is collected similarly to the collection of the baseline data. Once the baseline and test periods have been completed, the measured water-quality parameters and chemical-consumption data with and without the WCD in place are compared and assessed against manufacturer performance claims. The WCD must meet minimum reduction requirements established in the protocol and must also meet the manufacturer’s claimed conditioning performance.
The proposed test protocol and requirements developed by the task group are currently undergoing review and approval by the NSF Joint Committee on Recreational Water Facilities. This process is expected to continue for a few months and may result in minor changes being made. Ultimately, it is expected that the revised NSF/ANSI 50 will publish by early 2020. Until then, NSF is providing certification of WCDs under CCS-18325.
Meeting market needs
NSF and the NSF Joint Committee on Recreational Water Facilities are continuously working to meet the needs of the industry, of public health officials and of the general public by expanding and updating the requirements and scope of NSF/ANSI 50. Just as technology continues to evolve, so the standard must also evolve to keep pace with it. By developing CCS-18325, NSF created an immediate solution to help stakeholders establish the safety and efficacy of WCDs, plus it provided a springboard for the Water Conditioning Device Task Group to develop criteria to be incorporated into NSF/ANSI 50. These criteria are forward looking, covering not only numerous technologies and products in today’s market, but will also anticipate the development of new products and technologies in the coming years.
About the author
David Nance is the Business Unit Manager for NSF International’s Municipal Water Products and Recreational Water Products and works with NSF’s global testing, auditing and certification services for distribution system components and recreational water products. He has five years of experience in the Recreational Water program. Nance can be reached at email@example.com or (734) 827-5662.