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Pool maintenance: saltwater or fresh?

Both saltwater and fresh pools use some form of chlorine to keep water clean, clear and bacteria free. In freshwater pools, like this one in Sacramento, liquid chlorine is added as needed.
Both saltwater and fresh pools use some form of chlorine to keep water clean, clear and bacteria free. In freshwater pools, like this one in Sacramento, liquid chlorine is added as needed. Sacramento Bee file

More Americans are swimming on the salty side.

Saltwater is the fastest growing trend in aquatic entertainment, say pool experts. Ease of maintenance and much lower monthly expenses have made saltwater swimming pools common among hotels and resorts.

Saltwater pools also are in huge demand for home use. According to Pool & Spa News, 3 out of every 4 new in-ground pools are saltwater. In 2002, saltwater accounted for just 1 in 8 new pools. Of the nation’s estimated 5.1 million in-ground residential pools, about 1.4 million are now saltwater, according to industry statistics.

Saltwater swimming pools contain a tiny fraction of the salt in seawater – 3,000 to 5,000 parts per million compared to 35,000 ppm in the ocean.

California ranks as America’s No. 1 backyard pool state with more than 1.22 million in-ground residential pools and about 12,000 new pools installed each year. But preference of saltwater vs. fresh often comes down to what equipment was initially installed.

Conversion can cost $2,000 to $10,000, said Jose Torres of Bio-Active, makers of all-natural pool clarifier and cyanuric acid reducer.

“In the long run, it could be more economical,” Torres said. “Saltwater systems use salt chlorine generators to turn salt into usable chlorine. The best part is your pool has its own sanitation factory. As long as you provide enough salt, you have good, clean water.”

Kristin Barr, manager of All Clear Pool & Spa Supply in Sacramento, has seen a slow sea change in attitudes toward saltwater. In Sacramento’s older neighborhoods, traditional freshwater pools are still the norm.

“People who do have it love it,” Barr said of saltwater systems. “They wouldn’t change it for anything.”

Barr sees about equal pros and cons for saltwater systems.

“The pros for saltwater: You don’t have to add chlorine. The system creates its own chlorine,” she said. “The water is softer. People who are allergic to chlorine like to use saltwater because it’s much easier on their skin.

“On the con side, you need to add stabilizers such as cyanuric acid or your pool could lose its chlorine,” Barr said. “Saltwater systems don’t work well in winter when temperatures fall below 55 degrees, and you need to add chlorine. When it’s 100 degrees or higher in summer, you need to add chlorine, too, because the system can’t keep up with the pool’s chlorine demands.”

Added Torres, “The downside of saltwater pools is that you can have high concentrations of salt in the water. That salt can be corrosive and harder to deal with.”

And the most effective way of dealing with high salt is to empty the pool. The biggest savings come in maintenance. Saltwater systems use fine pool-grade salt, which is added directly to the water and replenished annually. For an average 15,000- to 20,000-gallon backyard pool, that salt costs less than $10.

“Once you add it, you’re pretty much done for the year,” Barr said.

Liquid chlorine and other chemicals needed by a freshwater pool cost $300 to $500 per year.

Both saltwater and fresh pools use some form of chlorine to keep water clean, clear and bacteria free. In fresh pools, liquid chlorine is added as needed.

Saltwater systems depend on a “salt cell” in its generator to create chlorine. The cell uses electrolysis to break salt – a sodium-chloride compound – into hydrogen gas and hypochlorous acid. The gas evaporates; the weak chlorine acid cleans the water. The salt compound reforms in the water and the whole process happens again.

That all-important salt cell needs to be replaced about every five years, a $500 to $700 expense.

“That’s where people figure the cost evens out between salt and fresh systems,” Barr said. “They have to replace the cell, and it’s so expensive.”

Pool water in general should be tested every two weeks to make sure its chlorine content is at a healthy level and its chemicals are balanced, Barr said. (Like most pool supply stores, All Clear offers free water testing for customers.)

“With traditional pools, you’re doing the chemistry,” she said. “Every 30 days, you’re adding chlorine. The saltwater system is always creating that chlorine for you. That makes saltwater pools attractive to people who travel a lot or aren’t around enough for regular pool maintenance.”

Call The Bee’s Debbie Arrington, 916-321-1075. Follow her on Twitter @debarrington.

Arguments for saltwater vs. freshwater pools


  • Ease of maintenance
  • System constantly replenishes chlorine
  • Pool can take care of itself for extended periods
  • Pool salt cheaper than liquid chlorine
  • Water feels softer
  • Less irritation to eyes, skin and hair


  • It came with the house
  • Purifies water year round at all temperatures
  • Conversion to salt chlorine generator is expensive
  • Replacement salt cells expensive, too
  • Salt can be highly corrosive, damage metalwork
  • Love of amateur chemistry and that chlorine scent