Chemical-free swimming pools are teeming with life
To keep pool water clean and clear, the industry has always turned to chlorine. But consumer demand for alternatives has prompted the emergence of new technologies. Los Angeles Times reports.
Saltwater systems came into vogue a few years ago, and copper-and-silver ionization and ozone-gas systems are becoming increasingly popular.
And then there are the ‘biologically active’ natural swimming ponds:
Unlike chemically treated pools, which are sterile, natural swimming pools contain plants and beneficial microorganisms that outcompete algae and harmful bacteria for nutrients, leaving water safe for swimming. In these natural pools, water is circulated with pumps to prevent mosquitoes from laying eggs.
While these are relatively new to the U.S., but more than 20,000 have been built globally. Some look like traditional pools with concrete foundations, hard edges and straight lines while others closely mimic nature, with gently sloping and planted edges. View a gallery here.
BioNova Natural Pools, a German company with North American headquarters in New Jersey, says it doesn’t use any sterilizers or chemicals of any kind. Their system uses shallow- and deep-water plants along with filters to keep the water clear.
Three have been built or are under construction on the east coast. Next year, they’ll install the first public natural swimming pool in the country at Webber Park in Minneapolis.
In California, Environmental Sculpturing has helped to design and install natural swimming ponds, such as a koi pond for people swimming in Topanga Canyon and a pond in Santa Monica that uses lava rocks to filter the water (it also has water hyacinths, lilies, irises, and horsetail rush).
Biologically active pools like the ones designed by BioNova and Environmental Sculpturing cost slightly higher to install compared with traditional pools, but the level of maintenance is roughly the same. Both types require vacuuming and hand skimmers to pick off surface debris. And while natural swimming ponds don’t need biweekly visits from a pool professional to add chemicals, they do require occasional weeding and replanting.
"One of the reasons why chlorine is the most popular swimming pool disinfectant is that it provides a long-lasting residual in the water," says Mary Ostrowski, director of chlorine issues for the American Chemistry Council in Washington, D.C. The group is working with an advisory council to provide information to consumers about various ways of keeping pools clean.
- Nature2 from Zodiac Pool Systems in Vista, Calif., dissolves traces of silver and copper into the water to disinfect it and prevent algae. The system, approved by the Environmental Protection Agency, allows pools to operate using just 0.5 part per million of chlorine, compared with the recommended 1 to 4 ppm for conventional pools.
- Wailani Natural Purewater Systems in Thousand Oaks, Calif., also uses copper and silver ionizers, as well as an ozone gas generator that virtually eliminates the need for chlorine.
[From Los Angeles Times]
Image: BioNova Natural Pools