If you hate the stink and sting of chlorine, you'll love saltwater pools.
Once primarily a perk in health spas and resorts, saltwater pools have now become popular among U.S. homeowners. Today, about 30% of all U.S. in-ground pools are saltwater.
How Saltwater Pools Work
Freshwater pools depend on store-bought chlorine to disinfect water and keep it free of algae, bacteria, and other health-harming organisms.
Saltwater pools rely on an electrolytic chlorine generator. The generator separates the salt in the pool water into its two primary elements, one of which is chlorine. The chlorine is then circulated into the pool to sanitize and disinfect the water.
The big advantage is that the process doesn't produce chloramines, an irritating byproduct of the store-bought chlorine traditionally used to disinfect pools. The chloramines are what give swimming pools that chlorine smell and sting your eyes.
Related: Swimming Pools: Alternatives to Chlorine
How Salty Are Saltwater Pools?
Saltwater pools have much lower salt concentrations — 3,000 to 5,000 parts per million — than the ocean does. Pool saltwater closely resembles the water that naturally bathes eyes and therefore, doesn't irritate them.
Saltwater Pool Benefits
Debbi Welch, who owned freshwater pools for 20 years, switched to saltwater nine years ago and says she'll never switch back.
"It's unbelievable how much easier it is to manage a saltwater pool," says Welch, a homeowner outside of Knoxville, Tenn.
Low maintenance: Add a few hundred pounds of salt when you open the pool for the season, swish it around to dissolve, then turn on the generator, and let it do its thing. No measuring, testing, or continually dumping more commercial chlorine into the water — although you may have to add more salt during the season. Welch dumped 500 pounds of salt into her 36,000 gallon pool, in late April, then added another 40 pounds in July.
Low annual costs: A salt chlorination generator makes chlorine at about $1 per pound, while off-the-shelf pool chlorine sells for $2 to $4 per pound. Welch says she used to spend about $800 per year to chlorinate her freshwater pool, but only $150 per year to chlorinate her saltwater pool.
Constant chlorine levels: Electrolytic chlorine generators automatically keep chlorine levels constant, which eliminates frequent testing for chlorine levels, and the need to buy, transport, and add chlorine.
Feels great: Swimmers in saltwater pools say the water feels silky and doesn't sting eyes or discolor hair like the water in freshwater pools can.
Saltwater Pool Drawbacks
Saltwater pools aren't perfect or perfect for every pool owner.
High startup costs: The top expense is the electrolytic chlorine generator, which ranges from $600 to $1,200, plus another $150 for installation.
Cell replacement costs: Salt cells inside the generator should be replaced periodically: sooner (in four to five years) if you use your pool year-round; later (maybe 10 years) if your pool season is only a few months a year. A cell costs $200 to $600.
Salt corrodes: Saltwater can corrode anything in or around your pool that contains metal, like lights, heaters, screws, diving board attachments, and patio furniture.
Salt stains: Saltwater splashing on soft stone on pool coping and decks can leave stains and pockmarks. Apply a sealant to solve this problem.
Related: Think Natural Swimming Pools are Icky? Think Again.