Moss making itself useful in city pools

  • Article by: JOHN EWOLDT , Star Tribune
  • Updated: June 11, 2012 - 7:31 AM

Swimmers praise the softer, clearer water in St. Paul's pools.


St. Paul uses sphagnum moss to clean its municipal pools. Many cities are trying other natural options.

Photo: Richard Sennott, Star Tribune

CameraStar Tribune photo galleries

Cameraview larger

Fifteen-year-old Anna Lundsten, of Hugo, rattled off the benefits to the Highland Park Aquatic Center in St. Paul, including hair that doesn't turn green anymore. She and the members of the STAR swim club of St. Paul and Roseville don't leave the pool stinking of chlorine, or with dry skin and burning eyes. "Even their swimsuits last longer with less chemicals," said her mom and swim coach, Sue Lundsten.

The cause of the odor-free pool water is a humble source: sphagnum moss. The St. Paul Parks and Recreation Department was the first in the country to start using the moss system to clean and condition the water in selected pools in 2009. Now the department uses it in all three of its pools, including the new Como Regional Park Pool.

Mike Hahm, director of Parks and Recreation for St. Paul, said the effort to go green is paying off.

"We're using about 50 percent less chlorine and less water, netting a small cost savings," he said.

David Knighton, inventor of the moss conditioning system, approached the city of St. Paul in 2008, offering it the chance to be the first to test the system in a large public pool. Prior to that, the moss treatment system had been used only in residential pools and home spas. In return, Knighton's company, Creative Water Solutions in Plymouth, monitored the system and provided the moss free of charge for a year. His company continues to oversee the program.

Here's how it works: The bacteria-inhibiting moss leaves, which are sterilized and dried until they resemble oatmeal, are then encased in what looks like a giant tea bag. The moss is currently sourced in New Zealand, but Knighton is doing field studies on harvesting the moss in northern Minnesota, where it also grows naturally.

Creative Water Solutions, which has sold conditioning for residential pools and spas under the names PoolNaturally and SpaNaturally since 2007, is still a microscopic drop in the bucket in the United States' $3billion pool water treatment business. After 10 years, the company has contracts at more than 100 commercial pool sites with more than 20 distributors nationwide, although Minnesota, its home base, remains its largest market.

Knighton attributes the slow growth to an industry that's highly suspicious of new products. "The water treatment industry has been looking for a less irritating way to condition water for years and most of them have had variable to little success," he said.

Minneapolis Parks and Recreation has also used the moss conditioning system in a limited number of wading pools and at Lupient Water Park in northeast Minneapolis. But it hasn't been able to cut back on the chlorine use, even with the moss, said Reggie Krakowski, facility manager at Lupient Water Park. He attributes that to an older, malfunctioning filter system last year, which has since been corrected. "We're hoping that we can safely use less chlorine this year. We like the system and we're sticking with it," he said.

As cities look for greener ways to maintain their pools, Minneapolis is looking for a first of its own -- the first natural treated pond in the country. Set to open at Webber Park in north Minneapolis next summer, it will look like a pool, and have swimming lanes and a beach, but the water will come from a nearby well and will be filtered through plant material, not chemicals.

Either way, pool partiers can enjoy cleaner water, minus the smell, itching and burning from too much chlorine. But even moss can't perform miracles. When certain solid, foreign substances are found, it's still time to clear the pool.

John Ewoldt • 612-673-7633 or

  • get related content delivered to your inbox

  • manage my email subscriptions


question of the day

Poll: Why do you most watch the Super Bowl?

Weekly Question





Connect with twitterConnect with facebookConnect with Google+Connect with PinterestConnect with PinterestConnect with RssfeedConnect with email newsletters