Swimming upstream: new products fight the backyard pool's chlorine addiction.

Anyone who has ever owned a swimming pool knows about being a slave to chlorine. Not only does the hapless pool owner have to buy the expensive chemical and lug it home for biweekly applications, but. also has to endure the stinging eyes, damaged hair, bleached clothing and nasty smell that goes along with it. The tradeoff has always been that chlorine works as advertised in killing bacteria and preventing algae from forming.

Brian Cohen of Environmental Working Group (EWG) says chlorine diluted in swimming pool water is probably not a human health threat. But chlorine is a harsh chemical whose use as a bleaching agent in the paper industry has polluted many rivers and streams (see "The Dead Pigeon River," Currents, May/June 1997). Fortunately, swimming pools and chlorine don't have to go together. On the market now are several natural alternatives to this time-honored chemical. According to Archie Beaton, executive director of the Illinois-based Chlorine-free Products Association, each of them uses a totally different approach,

Ready for Fish?

Aqua-Pure International makes a powdered crystalline chemical compound called Chlor-Free that, its makers say, eliminates the need for chlorine entirely and leaves the swimming pool so clean you can even keep tropical fish in it. Executive Vice President Dave Stuart, who's had Japanese koi in his pool for the past two years, says Chlor-Free "replaces the standard five chemicals with an all-in-one product that is non-corrosive, non-toxic and non-hazardous. The water is exceptionally clear, and there's no odor or taste." The chemical is dissolved in water and poured into the pool, so there are no gadgets to buy.

Chlor-Free is certified by the National Sanitation Foundation as approved for use in potable water supplies, and Stuart says you can, in fact, drink the treated water. He will not, however, reveal just what is in the patented product, beyond noting that it uses calcium for alkalinity, and copper sulphate to kill algae.

Chlor-Free was invented by a chemist in South Africa, and is widely used in Europe and Canada, though it was only approved for use in the U.S. last year. Stuart says homeowners will pay about 10 percent more than they would for conventional chemical systems. The product comes in five-, 10-, 20- and 50-pound containers, with about 60 pound -- costing about $480 -- being enough to maintain an average sized pool for a season.

Cutting Chlorine

Zodiac North American offers a system called Nature2 that doesn't do away with chlorine entirely, but it does greatly decrease the amount you'll need to use. A purifier device ($299 to $399, depending on the size of your pool) hooks into the filter line. Inside is a replaceable, coated ceramic cartridge (with a six-month life expectancy) that traps bacteria, algae and viruses and releases minute amounts of silver and copper into the pool. Silver is a bactericide whose properties have long been known. Copper kills algae. When used together they reduce chlorine needs by 90 percent.

Zodiac Marketing Director David Margolis says that the active ingredient copper sulphate -- present in both Nature2 and Chlor-Free -- is not dangerous in such small concentrations, and a 1991 Agriculture Canada study backs up his contention.

Another company, the Maryland-based Aqua-Flo, uses a natural byproduct of electricity to clean pool water. Aqua-Flo generators convert oxygen to ozone gas through a high-voltage electrical discharge and inject it into the pool's circulation line, where it dissolves in the water. According to President Al Cook, the ozone kills microorganisms on contact, then converts back into oxygen within 20 minutes without leaving any taste or smell in the water.

The Aqua-Flo system balances high initial cost -- about $2,500 to install the ozone generator in an average-sized poole -- against low maintenance costs. There are no chemicals to buy, and the generator uses no more electricity than a 100-watt bulb. Unlike Chlor-Free, however, Aqua-Flo's system does not replace every chemical in your pool. Consumers will still need to buy pH balancers, and chemicals to maintain alkalinity and total dissolved solids. Another drawback: Ozone gas can be toxic ill large doses. Cook says the generators strictly control the dosage, and there's no record of anyone dying from an overdose of inhaled ozone. In high concentrations (as in lightning strikes), ozone can have an unpleasant smell and leave people feeling nauseous. But John Passacantando, executive director of Ozone Action, says that the generated ozone doesn't remain in the water and should not present any health risks.

Unfortunately, only Mother Nature knows how to maintain a "swimming hole" that's totally natural, but at least with these new products you can cut down on the chlorine. CONTACT: Aqua-Flo, 6244 Frankford Avenue, Department T96, Baltimore, MD 21206/[phone]; Aqua-Pure International, 1001 North Highway One, Suite 206, Jupiter, FL 33477/[phone]; Chlorine-Free Products Association, 19 North Main, Algonquin, IL 60102/[phone]; Zodiac North American, 3420 NW 53rd Street, Fort Lauderdale, FL 33309/(800) 416-POOL.