Salt water vs chlorine pool
A salt water pool is a chlorine pool with its own chlorine maker: a cell turns dissolved salt into chlorine.
Always follow your product’s label directions. Pool and spa chlorine, bromine, shock and algaecides are EPA-registered pesticides: use products labeled for pool or spa use, and don’t swim or soak until levels are within the limit on your product’s label. If this page and a label disagree, the label wins.
On this page (8 sections)
Which one is cheaper depends on your chlorine use and local prices.
How a salt pool actually works
Salt (sodium chloride) is dissolved in the water at roughly 2,700–3,400 ppm, depending on the cell. The pump pushes water through the cell, where low-voltage current splits some chloride into chlorine. That chlorine dissolves into hypochlorous acid, the same sanitizer you get from liquid chlorine or tablets. After it has killed germs and oxidized dirt, it turns back into salt, and the cycle repeats. Pentair's manual puts it plainly: the generator only produces chlorine. It does not monitor or control chlorine levels.
So "salt vs chlorine" is really "chlorine made on site vs chlorine carried home." For comparison, seawater is about 35 parts per thousand, or 35,000 ppm (USGS). A pool at 3,200 ppm is about 9% as salty as the ocean, and many people cannot taste it. According to Hayward, people usually start to taste salt at around 3,500–4,000 ppm.
Comparison table
| Salt water (SWG) | Chlorine you add | |
|---|---|---|
| Where chlorine comes from | cell, every hour the pump runs | jugs, tablets, or granules you add |
| What you test | free chlorine (FC), pH, total alkalinity (TA), stabilizer (CYA), calcium hardness (CH), plus salt | FC, pH, TA, CYA, CH |
| Stabilizer (CYA) target | 60–80 ppm (Hayward); 30–50 (Pentair) | 30–50 ppm |
| Chlorine level | steady; set by output % and pump hours | peaks after each dose, drops before the next |
| pH drift | tends to rise; needs more acid | liquid chlorine: rises; trichlor tablets: falls |
| Stabilizer build-up | none from the cell | tablets add 0.6 ppm CYA per 1 ppm FC |
| Recurring purchases | salt after water loss, acid, cell every few years | chlorine all season, acid |
| Cold water | cells stop around 50–52 °F | works at any temperature |
| Shocking | still needs liquid chlorine | same product as daily use |
| Carrying and storing | salt bags, acid | heavy jugs or tablet buckets, acid |
Costs over 5 years (calculator)
The calculator above compares chlorine fairly: by what it costs to raise free chlorine by 1 ppm in your pool. Its example (15,000 gallons, 12.5% liquid chlorine at $6 a gallon, 2 ppm used per day) comes to $0.72 per ppm: about $10 a week, or $43 a month. The $6 price and the 2 ppm are example values; enter your own.
How much liquid chlorine does a season take? That depends mostly on how fast your pool uses chlorine. For a 15,000-gallon pool and a 150-day season:
| Chlorine used per day | 12.5% liquid chlorine | 10% liquid chlorine |
|---|---|---|
| 1 ppm | 18 gal (0.84 gal a week) | 22.5 gal |
| 2 ppm | 36 gal (1.68 gal a week) | 45 gal |
| 3 ppm | 54 gal (2.52 gal a week) | 67.5 gal |
Computed with our chlorine formula. Measure your daily use: test FC at dusk, then again the next dusk with no chlorine added.
To compare five years honestly, add up each side with your own quotes:
- Chlorine pool: gallons per season (table above) × your price × 5, plus acid.
- Salt pool: the cell and control (installed), plus replacement cells over 5 years, plus salt top-ups after rain and backwashing, plus extra acid, plus the electricity the cell uses, plus liquid chlorine for shocks and cold spring weeks.
Cell life makes the biggest difference. Pentair designs its IntelliChlor cell for about 10,000 hours, roughly five years of average use. We do not quote equipment prices because they vary by region and installer. Ask for a written quote that names the cell model. The chlorine cost calculator compares liquid, bleach, tablets, and cal-hypo (calcium hypochlorite) if you stay with added chlorine.
Maintenance differences
- Less daily dosing, not less testing. You still test FC and pH at least twice a week. You adjust a dial instead of pouring chlorine.
- More acid. Salt pools tend to drift up in pH. Plan on regular small acid doses, or lower alkalinity to slow the drift.
- Cell inspection every 2–3 months and an occasional acid wash (see caring for a salt pool).
- Salt top-ups after water leaves the pool. Evaporation does not remove salt.
- Stabilizer does not creep up the way it does with daily trichlor tablets, so you drain less often for high CYA.
- Winterizing has one more part. Hayward warns that freezing water damages the cell and its flow switch like plumbing, so in freezing climates the water has to come out of the pump, filter, and lines before the first hard frost. The control box itself can stay outside.
- Pool store tests need context. Hayward asks owners to tell the store they use a salt generator, so the advice you get fits a salt pool.
Disadvantages of salt water pools
- Up-front cost and a wear part. The cell has to be replaced periodically.
- Corrosion risk. Salt water is harder on some metals and natural stone. Hayward advises consulting a stone specialist before installing a salt system near natural stone coping or decking. Pentair warns that salt above 4,500 ppm can cause excessive corrosion.
- Rising pH and the scale that comes with it if you don't correct it.
- Cold-water shutdown. Early and late in the season, you may be back to adding chlorine by hand.
- Slow to shock. A cell adds chlorine too slowly to shock the pool. For algae, you still add liquid chlorine, dosed by its label.
- Equipment compatibility. New plaster must cure first (Hayward: 10–14 days; Pentair: at least one month), and heaters, pumps, and lights should be rated for salt. Check each manual.
Which is healthier?
Both pools are disinfected by the same chemical, hypochlorous acid. What matters for swimmers is keeping free chlorine and pH in range, which the CDC stresses for home pools regardless of the chlorine source. A salt pool's steadier chlorine level is a real advantage if you tend to miss doses. We did not find a primary study showing that one type is healthier for swimmers. Softer-feeling water is something many owners report, but it is a matter of taste, not a measured health benefit.
Switching? The salt conversion guide covers cell size, start-up salt, and new CYA and TA targets. All target ranges are on the chemistry chart, and the guide to chlorine types compares liquid, tablets, cal-hypo, and dichlor.
FAQ
What are the disadvantages of salt water pools?
Higher up-front cost, a cell that wears out, more acid for rising pH, possible corrosion of metals and natural stone, no chlorine production in cold water, and the need for liquid chlorine to shock. Salt must also be topped up after rain overflow and backwashing.
What is the healthiest pool to swim in?
The one with free chlorine and pH kept in range every day. Salt and added-chlorine pools use the same sanitizer. Neither is safe if chlorine runs low. Test at least twice a week and after heavy use or rain.
Is a saltwater pool really saltwater?
Mildly. Around 3,200 ppm of salt is about 9% of ocean salinity (about 35,000 ppm), so it is not like swimming in the sea, and many people cannot taste it. It is still a chlorinated pool.
Sources
- USGS, Why is the ocean salty? (about 35 parts per thousand): usgs.gov
- Hayward, AquaRite manual (how the system works, salt range, taste threshold, stone note, plaster cure): PDF
- Pentair, IntelliChlor SCG Installation and User's Guide, P/N 520589 Rev. R (2023) (overview, cell life, salt limits, plaster cure): PDF
- CDC, Home pool and hot tub water treatment and testing: cdc.gov
- Trichlor stabilizer build-up (0.6 ppm CYA per 1 ppm FC) and our chlorine formula: methodology