According to the company, Floatron, Inc. in Phoenix, Arizona, the device nearly eliminates the need for harmful chemicals such as chlorine. Company officials note that Floatron can reduce chlorine use by 80 percent, and other less hazardous purifying oxidizers may be substituted such as bromine, hydrogen peroxide or oxygen-based compounds.

As the device floats on water, sunlight is converted into electricity by the solar cells. The low-power current energizes specially alloyed mineral electrode below the waterline, causing the release of silver and copper ions into the surrounding water. Floatron costs nothing to power and operate. The only part requiring replacement is the mineral electrode, which will last approximately one to three swimming seasons and takes only a minute to change. Replacement cost is minimal, the company notes. Floatron retails for US$249.00 (www.floatron.com).