year-old architect and self-described “granola-head from way back,” began planning a pool for her home in Southampton, N.Y., she searched for a way to keep it sanitary without using chlorine. Glazer has been a swimmer for 30 years and was tired of dipping into chemically treated water. “I'd get out and my sinuses would be inflamed,” she said. “If I swam on a lunch break, I'd walk into the office smelling like chlorine.” Several pool experts she consulted told her that chlorine was the only option; others suggested a saline system, which uses sodium chloride, but because that produces chlorine in the pool, it did not address her concerns. Glazer eventually learned of a system that eliminates the need for chlorine and other chemicals, using a combination of ozone and copper and silver ions. That system can be added on to existing pools, at a cost ranging from $10,000 to $20,000. Because Glazer was starting fresh, she spent $60,000 to build her pool, which has a panoramic view of the ocean, roughly $20,000 more than if she'd built a chlorinated model. There are several ways to eliminate chlorine or significantly reduce the use of it, although the pool industry remains skeptical of their effectiveness and it is often difficult to find builders to install them. TechnoPure, a company based in Uxbridge, Mass., makes a system that pumps pool water through a chamber containing coated titanium plates which oxidize and burn off organic waste. Copper and zinc ions sanitize the water, resulting in a pool that's “virtually maintenance free in terms of chemicals,” said Chris Capozzoli, who founded the company seven years ago. He said the system costs around $5,500 for an average-size residential pool and can be installed during construction or added to an existing pool. Another company, DEL Ozone, based in San Luis Obispo, Calif., makes generators that inject ozone gas into the water as it recirculates, oxidizing bacteria and killing microorganisms. The generators are usually employed as a supplemental sanitizer to reduce reliance on chlorine, but according to Beth Hamil, vice president for corporate compliance and market development at DEL, it's possible to rely solely on ozone by using a larger generator and running the recirculating pump continuously. (Energy efficient pumps are available.) The so-called natural swimming pools that have slowly migrated to America from Europe are another option. The chlorine-free pools, which resemble ponds and must be built from scratch, circulate water through aquatic plants that act as organic cleansers. Alternative technologies aren't new (DEL began to sell ozone systems for pools and spas in 1980), but they have grown in popularity in recent years as people who dislike swimming in chlorinated water become aware of their options. “Our target audience is the person who shops at Whole Foods,” said Capozzoli, who expects to install about 700 residential systems this year, up from about 300 two years ago. Gus Paul, the owner of Gus Paul Pools in Port Washington, N.Y., said that although heater and filter sales are down due to the slowing economy, he has seen no drop in interest in the ozone units he carries. Glazer chose a treatment system by Wailani, a company based in Thousand Oaks, Calif., that uses both ozone gas and copper and silver ions to oxidize and sanitize pool water. But she had trouble persuading builders to install it. “They all said, it's not going to work,” Glazer recalled, admitting that she had doubts herself. “I was taking a leap of faith. But you have to. How many toxins do you want in your body?” Finally, the founder of Wailani, Tito Ignacio, flew to New York and supervised the installation. Neil Gross, a retired Wall Street futures trader who lives in Great Neck, N.Y., hired Paul three years ago to convert his backyard pool to an ozone system by DEL. Gross and his wife spent in the neighborhood of $10,000 on a chlorine-free system because, he said, “we don't like inhaling that chlorine smell.” He added, “if an organic will clean just as well, why not use it?” One reason: many in the pool industry still believe that chlorine is the best option, and as Glazer discovered, it's hard to find someone to build a pool that uses another system. “To my way of thinking, and the industry's, no one has come up with as effective a sanitation method as chlorine,” said Gene Fields, chairman of the Association of Pool and Spa Professionals. Fields, who said he had been in the pool business “since shortly after God invented water,” said he was skeptical of the effectiveness of systems that do not rely on at least small amounts of chlorine to kill bacteria. Donald Lapa, who runs Mister Poolman, a maintenance service in Los Angeles, also expressed doubts. “I think it's a fad, personally,” he said of systems that rely on ozone or ion generators. “People think it's softer on your skin. In my opinion, it isn't superior over the tried-and-true technique of chlorine and acid.” (Even Ignacio of Wailani admitted that if a pool gets severely out of balance, he sometimes uses chlorine to shock it before returning to the chemical-free method.) Lapa's skepticism reveals a potential problem with using a nonchlorine system: finding someone to maintain the pool. “If the maintenance people see a problem, their instinct is to throw chlorine in,” said Glazer, who went through four pool service companies until she found one willing to learn the Wailani system. The TechnoPure unit eliminates the need for a local pool maintenance company altogether: An on-site computer communicates with the company's headquarters, alerting technicians to problems and allowing them to make corrections to the water chemistry remotely. Some pool owners simply want to reduce their chlorine use, which is a much less expensive option. Sean Trotter, for instance, an air-conditioning business owner in Plano, Texas, installed an ozone generator by DEL to minimize chlorine use after his wife and daughter had reactions to chlorine. Ignacio, who said he spent two decades perfecting his nonchlorine system, mentioned common complaints of swimming in a chlorinated pool, like red eyes, dry skin and brittle hair. But Fields said those problems could be caused by factors other than chlorine, like pH imbalance or chemicals like bromine or dry acid that may be added to the pool. “A lot of people blame chlorine because it's so present,” Fields said, “but that's not entirely accurate.” Penny Burley, a retired television producer who lives near Ignacio in Thousand Oaks, said she and her husband swam happily in their chlorinated pool for 16 years. Then she became hypersensitive to chemicals and spent $12,000 to retrofit the pool with a Wailani system. “I was very worried about bacteria,” Burley said, but added that her fears have so far been unfounded. “If you open your eyes underwater it doesn't sting. If you swallow water you don't gag. Your skin feels like a baby's rear end. I don't think my skin would feel that good if the water was treated with chemicals or was dirty.” Despite the added cost and the complications she experienced in installing her nonchlorinated pool, Glazer is also __