Natural Pool-Owners Are Kissing Chlorine And Chemicals Goodbye

This coming summer, some homeowners will be swimming in their backyard pools au naturel. The iconic, aqua-blue vessels of chlorine-treated water are starting to see competition from the leafy, greenish waters of natural pools.

Waiting lists for in-ground pools and a chlorine shortage are sparking interest in these so-called bio pools, which are chemical-free. Swimmers are invited to lounge, naiad-like, close to water mint and water lilies as dragonflies hover.

“Prices are going through the roof on chlorine tabs—if you can even find them,” says Christopher Paquette of Robin’s Nest, a natural-pool company in Buxton, Maine.

Natural pools are a tiny fraction of the U.S. residential pool market, which is dominated by pools that use chlorine and other chemicals to keep bacteria and microbes at bay. They are a sustainable choice, requiring less energy to operate.

The result is green water—somewhere between a mossy hue to a jade colour. The roots of aquatic plants, such as water lilies, and materials like gravel create a naturally occurring ecosystem with biofilms called a regeneration zone. Water is kept clean and algae-free as it recirculates over the film of micro-organisms. Newer technology replaces this regeneration zone with a smaller, self-contained, plantless biofilter, which uses material such as lava rock and gravel to build up a biofilm.

The appeal to homeowners is water free of chlorine and other chemicals that keep pool water bacteria-free. Natural pools cost about $125 a square foot, excluding decks, electrical and landscaping. That is about 10% more than installation costs for a chlorine pool. But they are slightly less expensive to maintain. A traditional 500-square-foot pool costs about $1,800 to $3,200 a year during a season, according to Home Advisor.

The energy costs for a natural pool are one-half to one-third of a traditional pool, from $35-$50 a month, and there are no chemical costs. Natural pools can be made of a rubber membrane or gunite, and pool sides may be lined with river rock or special sand bags. Ladders, heaters, and diving boards can be added, but pool covers aren’t needed and water doesn’t need to be drained annually.

Liz and Steve Magoun, tech entrepreneurs in Rye, N.H., installed a natural pool at their home, where the couple like to cool off after long bike rides.

It wasn’t their first choice. Chlorine pools are prohibited in their development, where they recently built a 5,000-square-foot, shingle-style house. The development also prohibits saltwater pools, which turn salt into chlorine.

“It’s like swimming in a crystal-clear pond with a wonderful greenish hue,” says Mrs. Magoun. She says she finds the pool water more sublime than the chlorinated water the couple had in the two previous pools they owned. She did, however, insist that the aesthetic be “neat and manicured,” hence the biofilter, which does the work of plants grown in regeneration zones.

“Like many in the outdoor home-improvement business, we’ve been slammed with demand because of the pandemic,” says Allen Schnaak, vice president of business development at BioNova Natural Pools in Chester, N.J., which supplied the biofilter for the Magouns’ pool.

Mick Hilleary, owner of Total Habitat, based in Kansas City, Kan., says he saw demand shoot up nearly 30% over the past year. He says he installed a natural pool in Tennessee for environmentalist and former Vice President Al Gore four years ago.

Most natural pools in the U.S. are based on the European style. In Europe, 16% of residential pools are natural, compared with less than 1% in the U.S. Europeans use regeneration zones—water gardens filled with aquatic plants and other natural materials—to purify the water. That zone is equal in size to the swimming zone and often separated by a submerged stone wall or a waterfall feature.

In the U.K., architects Emma and Spencer Guy recently installed a 38-by-18-foot natural pool in Buckinghamshire, about an hour from London.

“There is nothing better than a swallow dipping next to you to drink as you swim in clean, odorless, warm water,” says Ms. Guy, 46. The pool complements the 3,000-square-foot, net-zero-energy house they designed and built.

“We sited the pond to bounce light back into the house,” says Mr. Guy, 47. “We enjoy seeing dragonflies, newts, pond skaters and kingfishers. The increased wildlife is the main reason we installed a natural pool.”

Their 34,000-gallon, black, vinyl-lined pool cost $56,000—about half the price of a typical natural pool—because they supervised much of the work themselves. A natural-pool company supplied the water-circulation kit and the planting medium for the two plant-filled regeneration zones. The plants are embedded in soil imported from Italy overlaid with a membrane and gravel.

Another way to cut costs is to convert an existing pool to a natural one, which runs about $60,000,” says Michael George, head of the U.K.-based Gartenart’s U.S. division in Jaffrey, N.H.

Mike and Heather Dooley, both 60, of Napa, Calif., installed a 30-by-60-foot natural pool in 2019, with decking and a beachlike area, for about $160,000. It is integrated into the landscape, Mrs. Dooley says. “It mimics swimming in a creek; we didn’t want a sterile environment.”

Blue heron, mosquito-eating dragonflies and frogs frequent the poolscape.

Natural pools require about as much work as a traditional pool to maintain. “We have to cut back the plants in the regeneration zone for the winter, treat water with beneficial bacteria a few times a season, drain pipes, and vacuum the bottom and sides of our natural pool,” says Avery Pierce, 70, of Buxton, Maine, whose natural pool was installed in 2006, for $50,000, including a complicated excavation.

“It looks good four seasons out of the year,” her husband, Tom Lanucha, 63, adds, saying he believes it won’t detract from the value of their home, as chlorine pools can in the Northeast. “You can skate on it in the winter.”

Reprinted by permission of The Wall Street Journal, Copyright 2021 Dow Jones & Company. Inc. All Rights Reserved Worldwide. Original date of publication: June 23, 2021.