Last updated: 2 June 2026
About 60% of Australian residential pools use a salt water chlorinator (SWG). The system has earned a permanent place in the Australian backyard for one reason: the chemistry is nearly automatic. You add salt to the pool once. The chlorinator cell converts dissolved salt into chlorine on demand. You don’t carry chlorine bottles, you don’t measure granules. For 8 months a year, the pool largely runs itself.
The honest catch: “saltwater pool” doesn’t mean “chlorine-free pool”. The salt cell produces the same chemical sanitiser as a chlorine pool, sodium hypochlorite, generated on-site. The difference is the delivery mechanism, not the chemistry. If your salt-pool diagnostic says “chlorine 0”, you have an SWG fault, not a chemistry breakthrough.
How a salt water chlorinator actually works
An SWG consists of three parts: a salt cell (titanium plates), a controller, and the pool’s plumbing. As water flows through the cell, the controller applies low-voltage DC current. The current splits dissolved sodium chloride into chlorine gas + sodium hydroxide, the chlorine dissolves into the water as hypochlorous acid, and you have free chlorine. After it sanitises (or breaks down under UV), it recombines back to salt. The salt is recycled, your salt level only drops through splash-out, evaporation refill water, and rain dilution.
Three things matter for cell performance: salt level, cell condition, and water flow rate. If any are wrong, chlorine output drops, and your “self-running” pool quietly stops sanitising. The most expensive mistake in saltwater pool maintenance is letting the cell scale up because you didn’t test salt monthly.
The salt-water-pool specific parameters
| Parameter | Saltwater target | Why it differs from chlorine pools |
|---|---|---|
| Salt (NaCl) | 3,000–4,500 ppm (cell-dependent) | Salt-pool-specific. Cell manufacturer’s spec is the law, Hayward AquaRite likes 3,200; Pentair IC needs 3,400; Astralpool VX models tolerate 4,000+. |
| Free Chlorine | 3–6 ppm typical, CYA-adjusted | Often runs higher than chlorine pools because saltwater owners set the cell at “always on” output. CYA targeting still applies. |
| pH | 7.2–7.6 (lower end) | Salt cells naturally drive pH upward because the chlorine-generation reaction produces sodium hydroxide. Expect to add acid more often than in a chlorine pool. |
| Total Alkalinity | 80–120 ppm | Same as chlorine pools. Stable TA blunts the pH-drift from the cell. |
| Cyanuric Acid | 60–80 ppm | Higher than chlorine-pool target. Salt cells generate at a steady rate; the higher CYA buffer prevents UV loss in mid-summer. |
| Calcium Hardness | 200–400 ppm | Same as chlorine. Watch for scale build-up on the salt cell itself. |
| Stabiliser | Same as CYA | If you’re outdoors and the cell can’t keep up by 11 am, your CYA is too low, not your salt. |
Australian SWG brands, what’s running on Aussie pools
Four manufacturers cover ~90% of installed Australian SWGs. They have different ideal salt levels and different failure modes:
Hayward AquaRite
The volume-leader. AquaRite cells need 3,000–3,400 ppm salt, work well in the 24–32 °C water temperature range, and warn via a “Low Salt” indicator below 2,700. Cell life: 3–5 years in soft water, 2–3 in hard water. The most common service issue is scale on the plates, flush in 1:10 muriatic acid annually.
Pentair IntelliChlor IC40
Premium, integrated with the IntelliConnect controllers. Likes 3,200–3,800 ppm salt. The IC40 is well-regarded for diagnostic detail, it reports cell-life percentage and tells you exactly why output is low. Cell life: 5+ years if maintained.
Astralpool VX9 / VX11
Australian-designed, common in pools built by Astralpool’s parent network (Splash, Crystal Pools). Tolerates higher salt levels, 3,800–5,000 ppm. The VX11 is a self-cleaning cell that reverses polarity periodically to dislodge scale.
Zodiac TRi / eXO
French-engineered, sold widely through Australian pool shops. The TRi-Pro is a strong mid-market unit; the eXO sits at the premium end with smart-home integration. Both want 3,500–4,000 ppm salt.
The cell-replacement reality: Salt cells are wear items. Expect $500–$1,200 to replace one (cells, not full chlorinators). They last 3–7 years depending on water hardness, run hours, and how well you flushed scale. Budget for it; don’t be surprised by it.
How to test salt level accurately
Three options, with different precision:
- Built-in cell salt reading. Convenient but unreliable as the cell ages. A cell that’s been scaled up will report low salt even when actual salt is fine. Use as a rough indicator only.
- Salt test strip. $1 per test. Accurate to ±200 ppm. Fine for “are we in the 3,000–4,000 zone?” decisions.
- Drop salt test (Taylor or AquaChek). Accurate to ±100 ppm. The reference standard for actual dosing decisions. Test monthly.
A worked example: bringing a saltwater pool back into balance
A 60,000 L outdoor pool with a Hayward AquaRite cell. Owner reports “the chlorinator says no chlorine but the cell light is green”. Tests:
- Salt: 2,400 ppm (low, should be 3,000+)
- FC: 0.5 ppm (well below minimum)
- CYA: 25 ppm (low, should be 60–80 for SWG)
- pH: 7.9 (high, typical SWG drift)
- TA: 110 ppm ✓
Diagnosis: the cell isn’t broken. Salt is too low to produce chlorine efficiently, CYA is too low to hold the chlorine the cell does produce against UV, and the high pH is reducing what little chlorine activity remains. Three problems compounding.
Fix order:
- Add salt: raise from 2,400 → 3,200 = 800 ppm × 60,000 L = 48 kg of pool salt. Add over 24 hours with pump running. Re-test salt the next day.
- Add CYA stabiliser: raise from 25 → 65 = 40 ppm × 60,000 L = 2.4 kg of cyanuric acid. Dissolve in a bucket first, add through the skimmer.
- Lower pH: 250 mL muriatic acid (~32%).
- Boost chlorine manually while the cell catches up: 1 L liquid chlorine to get FC to ~5 ppm immediately. By tomorrow, the cell will hold it.
The result: By 48 hours later, FC is steady at 4–5 ppm, the cell light is green, salt is in spec, and the pool returns to “set and forget” mode. Total cost: about $80 in chemicals. No service call.
Why your saltwater pool still needs cyanuric acid
This trips up almost every new saltwater pool owner. The cell makes chlorine. Why do you need stabiliser?
Because the chlorine the cell makes is identical to chlorine you’d add from a bottle, it’s hypochlorous acid in solution. UV destroys it the same way. Without CYA, the cell would need to run 14+ hours a day in summer just to replace what UV burns off. With CYA at 60 ppm, the cell needs maybe 6 hours a day. CYA exists to make your cell’s chlorine last long enough to actually sanitise the water, not just to disappear into the sky.
The mistake I see most often: saltwater owners reading “CYA target 30–50 ppm” generic chlorine-pool advice and keeping their SWG pool at 30 ppm. Their cell then can’t keep up with summer demand, they crank the output dial to 100%, and the cell wears out twice as fast as it should.
Troubleshooting saltwater pool problems
| Symptom | Most likely cause | Fix |
|---|---|---|
| Cell shows “Low Salt” but test strip says salt is fine | Scale on cell plates | Soak cell in 1:10 muriatic acid for 15 minutes. Flush. Re-install. |
| Pool drifts toward high pH every week | Normal SWG behaviour, the chlorine-generation reaction produces sodium hydroxide | Add muriatic acid weekly. Expect ~100–200 mL per 50,000 L per week in summer. |
| Salt level keeps dropping | Splash-out, backwash, or fresh-water top-up after rain | Add salt as needed. Expect ~5–10 kg per month in a busy outdoor pool. |
| FC won’t hold despite cell running 100% | CYA too low OR cell at end-of-life | Test CYA first. If < 50 ppm, add stabiliser. If CYA is OK and cell still won’t produce, replace cell. |
| White scale on cell plates | High calcium hardness + high pH | Acid-flush cell. Lower pool pH to 7.2 going forward. If CH > 500, partial drain. |
Sources & references
- Trouble Free Pool, ABCs of Pool Water Chemistry (community-developed reference based on the Pickens method)
- ANSI/APSP-11, Water Quality Standards in Public Pools (Association of Pool & Spa Professionals)
- AS 3633-1989, Private swimming pools (water quality) (Australian Standard)
- Taylor Technologies K-2006C Complete Pool Test Kit (FAS-DPD reference standard)
Frequently asked questions
Do saltwater pools have chlorine in them?
Yes. The salt cell converts dissolved salt into chlorine on demand. The chemistry of the water is identical to a chlorine pool, sodium hypochlorite (the same active sanitiser) is in the water either way. The difference is just the delivery mechanism. A ‘saltwater pool’ is more accurately called a ‘salt-water-generated chlorine pool’.
Can you taste the salt in a saltwater pool?
Most people can’t. Saltwater pools run at 3,000–4,500 ppm salt. Seawater is around 35,000 ppm, roughly 10× saltier. The salt is detectable if you swallow water, but it’s far below ocean-water levels and roughly the same as a teardrop.
How often do you need to add salt to a saltwater pool?
Less than you’d think. Salt doesn’t degrade, it’s recycled through the cell. You add salt for splash-out, backwash water loss, and rain dilution. A typical Australian residential pool needs 10–30 kg of salt per year, mostly added after heavy rain or major water-loss events.
How long do salt cells last?
3–7 years depending on water hardness, pool size, run hours, and maintenance discipline. Soft water and acid-flushing the cell annually extends life. Hard water and ignoring scale build-up shortens it. Expect to spend $500–$1,200 replacing a cell when it eventually fails.
Is it cheaper to run a saltwater pool than a chlorine pool?
Marginally cheaper on a per-week basis (no buying chlorine), but salt cells are wear items. Over a 5-year period, total cost is roughly comparable, saltwater wins on convenience, chlorine pools win on initial capital cost. Salt pools also drift toward high pH and need more acid additions than chlorine pools.
Should I close my saltwater pool in winter?
Most Australian saltwater pools run year-round at reduced output. The cell can stay in service as long as water temperature stays above ~15 °C. Below 15 °C, cell output drops and many owners switch to occasional manual liquid chlorine top-ups.
Can the Water Test Calculator app handle saltwater pools?
Yes. The app has a dedicated saltwater pool profile that handles salt level, CYA-adjusted free chlorine targets, and the typical pH-drift behaviour of SWG-generated chlorine. Launching on iOS and Android in approximately 10 days.
Saltwater pool testing, done right
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