A salt water pool is a chlorine pool — it just makes its own. You dissolve pool-grade salt to around 3,200 ppm, about a tenth of ocean salinity, and a salt chlorine generator splits it into chlorine by electrolysis. The chlorine sanitizes, then recombines back into salt. The chemistry targets you test for are identical to any chlorine pool.
How Salt Water Pools Work
A salt water pool is a chlorine pool. The difference is where the chlorine comes from. Instead of adding liquid chlorine or tablets by hand, a salt chlorine generator (SWG) makes chlorine from dissolved salt in the water through electrolysis.
The cycle runs in four steps:
- 1.You add pool-grade salt (sodium chloride) to roughly 3,200 ppm — about a tenth the salinity of ocean water.
- 2.The SWG cell, plumbed into the return line after the filter, passes current through titanium plates coated with ruthenium or iridium.
- 3.That current splits the salt (NaCl) into sodium and chlorine, and the chlorine sanitizes the water.
- 4.The chlorine then recombines with the sodium back into salt — so the salt is not consumed, and the cycle repeats.
Key misconception
"Salt water pools don't use chlorine" is the most common myth in pool ownership. They absolutely do — the SWG generates hypochlorous acid, the exact same sanitizer that liquid chlorine produces. The water chemistry rules (FC, pH, CYA, TA, CH) are identical. The only difference is the delivery method.
Salt vs Chlorine — The Truth
The marketing around salt water pools exaggerates the differences. Here's what's actually different and what's not:
| Factor | Traditional chlorine | Salt water (SWG) |
|---|---|---|
| Sanitizer | Chlorine (added manually) | Chlorine (generated from salt) |
| Water feel | Neutral | Slightly softer (dissolved salt) |
| CYA buildup | Risk with trichlor tabs | None — SWG produces unstabilized chlorine |
| pH tendency | Varies by chlorine type | Rises constantly (electrolysis produces NaOH) |
| Upfront cost | Low (just chemicals) | $1,000–2,500 for the SWG unit |
| Ongoing chemical cost | $30–60/mo (liquid chlorine) | $5–15/mo (salt + acid) |
| Cell replacement | N/A | $400–900 every 3–7 years |
| Corrosion risk | Low | Higher — salt attacks metal fixtures, stone coping, and some deck materials |
Advantages of Salt Water
No CYA buildup
The SWG produces pure, unstabilized chlorine. You add CYA once to the desired level (30–50 ppm) and it stays there. With trichlor tabs, CYA climbs relentlessly all season and eventually forces a partial drain.
Steady chlorine output
The SWG runs whenever the pump runs, producing chlorine continuously. No more forgetting to dose or coming home to a green pool after a weekend away.
Softer-feeling water
The dissolved salt (about 3,200 ppm) gives the water a noticeably softer feel. Most swimmers prefer it, though the difference is subjective and some people don't notice it at all.
Lower chemical spend
Once the salt is in, you're mostly buying muriatic acid for pH control. Monthly chemical cost drops significantly compared to buying liquid chlorine or tabs.
No storing or handling chlorine
No jugs of bleach, no bucket of cal-hypo granules, no chlorine gas risk. Salt bags are inert and safe to store anywhere.
Disadvantages of Salt Water
Upfront cost
A quality SWG (Hayward, Pentair, Jandy) costs $1,000–2,500 installed. Budget units exist but tend to have shorter cell life and weaker output.
Cell replacement
The electrolytic cell wears out. Most cells self-clean by reverse polarity (periodically flipping the current to shed calcium scale), but hard-water pools still need an occasional muriatic-acid wash. Keep salinity in the typical 2,700–3,400 ppm window to protect the plates. Expect 3–7 years depending on usage, water balance, and cleaning habits. Replacement cells run $400–900 — a cost that traditional chlorine pools don't have.
Corrosion
Salt is corrosive. It attacks metal handrails, ladders, light fixtures (unless sealed/bonded), and natural stone coping and decking. Some pool builders won't warranty stone work on salt pools. Galvanic corrosion of dissimilar metals is a known risk — a sacrificial zinc anode helps but doesn't eliminate it.
pH rises constantly
Electrolysis produces sodium hydroxide (lye) as a byproduct, pushing pH up relentlessly. Salt pool owners add muriatic acid weekly — often more than traditional pool owners. This is the single most common complaint.
Cold weather limitation
Most SWG cells stop generating below 60°F (16°C) water temperature. In cold climates, you'll need to supplement with liquid chlorine during shoulder season — the SWG can't carry the pool alone year-round.
Cost Comparison
Salt water saves on chemicals but costs more upfront and has a recurring cell replacement expense. Here's a realistic 10-year comparison for a 15,000-gallon pool:
| Cost item | Traditional (10 yr) | Salt water (10 yr) |
|---|---|---|
| SWG unit | $0 | $1,500 |
| Cell replacements | $0 | $600–1,200 |
| Initial salt | $0 | $100–150 |
| Chlorine/chemicals | $3,600–7,200 | $600–1,800 |
| Acid (pH control) | $200–600 | $400–1,000 |
| 10-year total | $3,800–7,800 | $3,200–5,650 |
Estimates based on HomeAdvisor 2024 chemical cost ranges and manufacturer SWG pricing (Hayward Aqua Rite, Pentair IntelliChlor). Actual costs vary by region, pool size, and usage.
Bottom line
Over 10 years, salt water is modestly cheaper for most pools — but the savings aren't dramatic. The real reasons to switch are convenience (no handling chlorine, steadier FC levels) and water feel, not cost savings.
Run your own numbers with the Maintenance Cost Calculator and Cost of Ownership Calculator.
Salt Water Pool Maintenance
Everything in the weekly maintenance guide applies. Salt pools add a few extra tasks:
Weekly
Check and adjust pH
The SWG pushes pH up constantly. Test 2–3× per week and add muriatic acid as needed. This is the most frequent task on a salt pool.
Check FC level
The SWG should maintain FC automatically, but verify. If FC is low, increase the SWG output percentage or run time. If consistently low, the cell may need cleaning or replacement.
Monthly
Test salt level
Target 3,200 ppm (varies by manufacturer — check your SWG manual). Salt leaves the pool through splash-out, backwash, and rain dilution. Add pool-grade salt (not table salt or rock salt with anti-caking agents) when it drops below the target. Most SWGs display the current salt reading.
Inspect the SWG cell
Look through the cell for white calcium scale on the plates. Light buildup is normal. Clean when you see significant deposits — a scaling cell loses efficiency and dies faster.
Every 3 months
Clean the cell (if needed)
Soak in a mild acid solution (4:1 water to muriatic acid) for 5–15 minutes until the scale dissolves. Rinse thoroughly. Don't scrape — you'll damage the coating. Some SWGs have a self-cleaning reverse-polarity feature that reduces but doesn't eliminate manual cleaning.
Cell longevity tip
The number-one cell killer is running it at high output in unbalanced water. Keep pH below 7.6 (lower is better for the cell), keep calcium hardness under 400 ppm, and don't run the cell at 100% output unless you need to — 50–70% is plenty for most pools. A well-maintained cell lasts 5–7 years; a neglected one may die in 2.
Making the Switch
Converting a traditional chlorine pool to salt water is straightforward:
Choose the right SWG size
Size the SWG for your pool volume. Manufacturers rate cells by maximum gallons — buy one rated for at least 1.5× your pool size so you can run it at 50–70% output instead of 100%. This extends cell life significantly. Use the Salt Calculator to find how much salt you need.
Install the cell and control box
The cell installs in the return plumbing after the filter and heater (salt + acid will damage a heater if it goes before). The control box mounts nearby with power and a flow sensor connection. Most handy homeowners can DIY this; otherwise, a pool tech can do it in 2–3 hours.
Add salt
Broadcast pool-grade salt around the pool perimeter with the pump running. It takes 24–48 hours to fully dissolve and circulate. Don't turn on the SWG until the salt level reads in range on the control box.
Balance the water
Make sure CYA is at 30–50 ppm, pH at 7.2–7.6, TA at 80–120 ppm, and CH below 400 ppm before starting the SWG. High calcium + high pH + electrolysis = rapid cell scaling.
Protect metal fixtures
Install a sacrificial zinc anode in the plumbing or skimmer basket to absorb galvanic corrosion. Check metal handrails and ladders — if they're not properly bonded to the equipment bonding grid, the salt will eat them. A qualified electrician can verify bonding.