Moss-based pool filter shows promise as chlorine alternative

Highland Park Aquatic Center
The Highland Park Aquatic Center in St. Paul.
Courtesy of the City of St. Paul

A moss-based water filtration system testing in St. Paul this summer has shown promise as a way to keep pools clean while using fewer chemicals, city officials said.

St. Paul Mayor Chris Coleman and David Knighton, president and CEO of Creative Water Solutions, today unveiled the preliminary results of the program that company officials claim is the nation's first public pool to use the moss-based water treatment system.

"St. Paul continues to be a national leader when it comes to embracing innovative green practices like this moss-based filtration system for public pools," Coleman said in a statement. "We're bringing immeasurable environmental benefits to our residents and pool users, generating cost savings for taxpayers, and helping a Minnesota company grow."

The pilot was undertaken at the beginning of the summer season with the Minnesota-based company, which already markets the moss-based system for residential pools and spas.

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The project involved installing a series of canisters housing the water conditioning sphagnum moss that work along with state-mandated chemical systems.

The project models nature's ability to condition water by controlling the growth of microorganisms such as bacteria, algae and other waterborne agents and by reducing metals and other deleterious elements, according to the company's website.

The initial results of the study show significant reduction in chemical usage, such as chlorine and cyanuric acid, less time for maintenance due to reduction in backwashing and algae growth, less chemical corrosion of pipes, heaters, pumps and liners, and less costly repairs and higher customer satisfaction, city officials said.

"This was an ideal pool setting to conduct our experiment," Knighton said.

"We were successful in significantly lowering the pool's chemical loads, especially chlorine, and creating more natural water conditions and less harmful impacts to swimmers' bodies and suits, and pool hardware," said Knighton, adding that the system also meets all city and Environmental Protection Agency standards.