Salt water pool maintenance
A salt water pool is still a chlorine pool: the cell turns dissolved salt into chlorine, so you test free chlorine (FC) as in any other pool.
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)
The cell needs about 3,200 ppm of dissolved salt. With stabilizer (cyanuric acid, CYA) at 70 ppm, keep FC at 3.5–5.5 ppm, and expect pH to rise between tests.
The calculator above starts from a typical salt pool that has drifted: 15,000 gallons, FC 1 ppm, pH 7.8, alkalinity 70, CYA 60, and salt 2,800 ppm. It returns the steps in order, with doses for the products you pick. Change the numbers to your own test.
Targets for salt pools (salt, CYA, and FC at 5% of CYA)
A salt chlorine generator (SWG, also called a salt cell or chlorinator) changes where chlorine comes from, not what chlorine does. The water still needs FC, pH, total alkalinity (TA), calcium hardness (CH), and CYA in range. Two numbers are different from a pool you chlorinate by hand: salt, and how high you keep CYA.
| Parameter | Our target for salt pools | Hayward AquaRite manual | Pentair IntelliChlor guide |
|---|---|---|---|
| Salt | your cell's number, default 3,200 ppm | 2,700–3,400 ppm, 3,200 optimal | 3,200–3,400 (quick start); 3,600 (user's guide) |
| CYA | 60–80 ppm | 60–80 ppm | 30–50 ppm |
| Free chlorine | at least 5% of CYA (table below) | 1.0–3.0 ppm | 2.0–4.0 ppm |
| pH | 7.4–7.6 | 7.2–7.8 | 7.2–7.8 |
| Total alkalinity | 60–90 ppm if pH keeps rising, otherwise 80–120 | 80–120 ppm | 80–120 ppm |
| Calcium hardness | 200–400 ppm (plaster) | 200–400 ppm | 200–400 ppm |
Manuals read on 2026-09-29. The two brands disagree on CYA and salt. For salt, follow your own cell's manual.
Why do we pair a higher CYA with a free chlorine target that scales with it? Stabilizer shields chlorine from sunlight but also holds part of it in reserve, so the same FC reading does less work at higher CYA. The CDC's model code describes this principle. A cell adds chlorine slowly every hour the pump runs, so a salt pool can hold a lower FC-to-CYA ratio than a pool dosed once a day. We use a minimum of 5% of CYA for salt pools and 7.5% for hand-dosed pools:
| CYA | Salt pool: minimum FC | Salt pool: target range | Hand-dosed pool: minimum FC |
|---|---|---|---|
| 60 ppm | 3 ppm | 3–5 ppm | 4.5 ppm |
| 70 ppm | 3.5 ppm | 3.5–5.5 ppm | 5.5 ppm |
| 80 ppm | 4 ppm | 4–6 ppm | 6 ppm |
| 90 ppm | 4.5 ppm | 4.5–6.5 ppm | 7 ppm |
Our parameterization, not a table from any manual. Full reasoning and sources on the methodology page.
Note the conflict with the manuals: Hayward lists 1.0–3.0 ppm, which works at low CYA but is low at CYA 80 ppm. Product labels also set limits for swimming. Stay within your target range, and see the chlorine level guide for how FC, CYA, and label limits fit together. All other ranges are on the pool chemistry chart.
Why pH keeps rising in a salt pool
The chemistry inside the cell is close to pH-neutral overall: chlorine is made, does its job, and turns back into salt. The rise comes mostly from carbon dioxide leaving the water. Fine gas bubbles from the cell, jets, waterfalls, and spillovers all push CO2 out, and each bit that escapes nudges pH up. The higher your TA, the more CO2 the water holds and the faster pH climbs.
What helps, in order of effect:
- Lower TA to about 60–90 ppm. Less carbonate in the water means less CO2 to lose, so pH rises more slowly. Check your saturation index (LSI) afterward so the water does not turn corrosive.
- Add muriatic acid in small, regular doses instead of one big correction. Both Hayward and Pentair discourage dry acid (sodium bisulfate) in dry climates, where its byproducts build up and can damage the cell.
- Consider borates at 30–50 ppm. They buffer pH against the upward drift (PHTA). Adding borax raises pH at first, so you lower it with acid afterward.
- Reduce aeration when no one is enjoying the waterfall.
How much acid? The guide to lowering pH works out the dose from your pH, TA, and CYA.
Setting the chlorinator output %
The output % is the share of each pump hour that the cell spends making chlorine. Your daily chlorine production depends on three things you control: pump hours, the output %, and salt level. Hayward's advice is practical: start near 50%, test FC every few days, and adjust. It usually takes two or three changes to find your setting.
- Raise the % in summer heat, after heavy swimming, and as the cell ages.
- Lower it in cool weather and when the pool is covered. Pentair recommends lower output under a cover.
- Cells stop in cold water: the AquaRite below 50 °F, the IntelliChlor below about 52 °F. In spring, you may need liquid chlorine until the water warms.
- "Boost" or "super chlorinate" runs the cell at 100% for 24 hours. That helps after a party, but it raises chlorine far more slowly than a shock product added by hand.
If the pump runs only a few hours, even 100% may not be enough. The pump run time calculator shows how long one turnover of your pool takes.
Weekly routine
- Twice a week: test FC and pH. Adjust the output % for FC. Add acid if pH is above 7.6.
- Weekly: empty skimmer and pump baskets, brush, and check that the cell's flow light shows normal flow.
- Monthly: test TA and salt (Pentair suggests monthly checks of salt, CYA, CH, metals, and total dissolved solids, or TDS).
- Every 3 months, or when your filter is cleaned: test CYA and CH, and open and inspect the cell (Hayward's schedule).
- After heavy rain or a backwash: retest salt 24 hours later and top up with the salt calculator.
Cell care
Most cells clean themselves by reversing polarity every few hours, which sheds light scale. In hard water or out-of-balance water, white crust still builds on the plates and cuts output. Hayward says that buildup points to high calcium in the pool. The step-by-step acid wash, and when not to do it, is in how to clean a salt cell. Keeping the saturation index near zero is the best prevention.
Green or cloudy salt pool
A salt pool turns green for the same reason any pool does: free chlorine fell too low for its CYA. The difference is the list of likely causes, because something stopped the cell from keeping up:
- Salt too low. Many cells cut output, then stop, below their range (Pentair: reduced below 2,800 ppm, off below 2,600).
- Cold-water cutoff in spring or fall, or a shortened pump schedule.
- Scaled or worn cell. It makes less chlorine than its setting suggests.
- CYA too high, so the FC you have is too weak. Test CYA before anything else if you haven't tested it in months.
- High chlorine demand from nitrates or phosphates, which Pentair says can consume chlorine as fast as the cell makes it.
The cell cannot clear algae on its own. Shock with liquid chlorine following your product's label directions, brush, run the filter, and retest daily until the water is clear and chlorine holds overnight. Then fix the cause above. Full recovery steps are in the green pool guide. Cloudy water with good chlorine is usually a filtration or calcium problem instead: see cloudy pool water.
Safety
Salt pools use more acid than most pools, so store muriatic acid and liquid chlorine apart and never mix them: together they release chlorine gas. Add acid to water, never water to acid, and wear gloves and eye protection. Don't swim while you are shocking or right after adding acid. Wait until a retest shows levels in range. If chemicals get in someone's eyes or are swallowed, call Poison Control at 1-800-222-1222. Always follow the product label. It is a violation of federal law to use a pesticide product in a manner inconsistent with its labeling. See the chemical safety guide.
FAQ
How to treat a salt water pool?
Treat it like a chlorine pool with a built-in chlorine feeder. Test FC and pH twice a week, keep CYA at 60–80 ppm and FC at least 5% of CYA, lower pH with muriatic acid as it rises, keep salt in your cell's range, and inspect the cell about every 3 months. Shock with liquid chlorine when needed, dosed by its label, since the cell adds chlorine too slowly to shock the pool.
Why is my salt water pool green?
Chlorine dropped below what your CYA requires, usually because the cell slowed down: low salt, cold water, short pump hours, a scaled or worn cell, or very high CYA. Shock with liquid chlorine to clear the algae, then find and fix the reason the cell fell behind.
Why is my pool using so much salt?
Salt leaves only with water: backwashing, splash-out, rain overflow, draining, or a leak. Evaporation leaves it behind. If salt keeps dropping with no obvious water loss, check for a leak, and confirm the reading with a second test method before adding more. A cell that underreads can make it look like salt is vanishing.
Sources
- Hayward, AquaRite electronic chlorine generator manual (salt, stabilizer, output %, inspection schedule, maintenance table): PDF
- Pentair, IntelliChlor SCG Installation and User's Guide, P/N 520589 Rev. R (2023): PDF; Quick Start Guide and Tips, P/N 520943 Rev. D (2023): PDF
- CDC, Model Aquatic Health Code 2024 Annex (chlorine and cyanuric acid): PDF
- PHTA, Technical Bulletin on borates: phta.org