Swimming Pool Salt Use
How common are salt water pools?
Salt water pools were developed in Australia in the 1960s and currently account for about 80 percent of all pools there. They were first introduced in the United States in the 1980s and became very popular in the mid-1990s as the technology improved. In 2007, salt water pools accounted for nearly three-quarters of new pool installations, up from about 15 percent in 2002. There are about 1.3 million salt water pools in the U.S. today. (Sources: P.K. Data; Pool & Spa News 3/30/08)
How do salt water pools work?
Both salt water pools and traditional chlorine pools use chlorine to sanitize the water. The difference is that salt water pools use a chlorine generator to produce natural chlorine from salt by separating salt molecules into their component parts: chloride and sodium. After salt is converted to chlorine to sanitize and oxidize the water within the generator, chlorine converts back to salt when it re-enters the pool, and the process continues over and over again, conserving the salt and keeping sanitizer levels balanced.
Traditional pools, on the other hand, require the pool owner to add chlorine and other chemicals on a regular basis, because the chlorine is “consumed” as it sanitizes the water. Traditional chlorine pools can be easily converted to salt water pools by purchasing and installing a chlorine generator.
What are the benefits of salt water pools?
The growth of salt water pools has been driven by consumer enthusiasm about their benefits, which include:
- Water that’s gentler on skin, eyes, nose and hair. Salt water pools have approximately one-tenth the salinity of ocean water and about one-third the salinity of human tears. Swimmers enjoy the soft feel of the water, and it’s more soothing to skin and hair and easier on eyes and noses than the water found in traditional chlorine pools. And there’s no unpleasant chlorine smell.
- Simplified, more convenient maintenance. Because salt water pools generate their own chlorine, pool owners don’t have to buy, transport, store and handle hazardous chlorine chemicals. And when owners use salt specifically formulated for salt water pools, maintenance is simpler than with traditional chlorine pools and saves time and money.
- Environmentally friendlier. Routine pool maintenance doesn’t involve the handling and storage of manufactured chlorine and lessens the need for other potentially hazardous chemicals.
How should I care for my salt water pool?
- Use only high purity solar or evaporated salt that has been specifically designed for salt water pools. Many of the lower-cost, generic salts sold for pool use contain a host of contaminants that can affect water clarity and cause staining, scale, and overall water balance issues.
- Use only treatment products that have been designed specifically for salt water pools. Products designed for traditional pools often contain ingredients such as sulfates and phosphorous-based sequestrants that can cause scale in the chlorine generator. In the unique environment of salt water pools, they also can break down into compounds like orthophosphates, which are nutrients for algae and can contribute to scale. Scale will dramatically shorten the life of a chlorine generator.
- Test and balance your pool regularly. For residential pools, aim for weekly testing of pH and chlorine and monthly testing during the season for total alkalinity, calcium hardness, metals, and cyanuric acid (a chemical that extends the life of chlorine in a pool). Monthly testing of salinity levels is also recommended to ensure they are maintained at the proper level indicated by the manufacturer of your chlorine generator.