The first thing to get straight: a salt water pool is chlorinated. The cell electrolyses dissolved salt into chlorine, the chlorine sanitises the water, and then it reverts to salt and the cycle repeats.
Nobody is choosing between salt and chlorine. They are choosing between buying chlorine and making it, and that is a straightforward capital-versus-consumable comparison.
Up-front
| Item | Cost |
|---|---|
| Salt system, 20k gal, installed | $1,400–2,200 |
| Initial salt charge, ~600 lb | $60–120 |
| Electrical work, if required | $0–400 |
| Total to convert | $1,460–2,720 |
Nothing on the traditional side. A chlorine pool needs a bucket.
Running, per season, 20,000 gallons
| Line | Salt | Liquid chlorine |
|---|---|---|
| Sanitiser | $45 electricity | $230 |
| Salt top-up | $25 | — |
| Muriatic acid | $95 | $55 |
| Stabilizer | $20 | $30 |
| Everything else | $190 | $195 |
| Season | $375 | $510 |
The salt pool saves $135 a season on consumables. Note the acid line runs nearly double: chlorine generation produces sodium hydroxide as a by-product and drives pH up continuously, so a salt pool needs acid every week rather than every fortnight.
The cell
This is the line that decides the whole comparison, and it is the one left out of most sales conversations.
A salt cell has a finite life measured in hours of generation — typically 10,000 hours, which is 4 to 7 seasons depending on pool size, run time and how hard the cell works. Replacement runs $500–900.
Amortised, that is $85–180 a season, which consumes most of the $135 saving and in a small pool exceeds it.
Cell life shortens with:
- High CYA or scale. Calcium scaling on the plates is the standard cause of early failure, and it is a water-balance problem rather than a cell problem.
- Running the system hard. A cell sized for the pool it is on works at 50–60% output and lasts. A cell sized one class small runs at 90% and dies years early — and undersizing is the most common installation error, because the smaller cell is cheaper to quote.
- Cold water. Most cells stop generating below about 60 °F, which is not damage but does mean a shoulder-season pool still needs liquid chlorine.
Ten years, 20,000 gallon pool
| Salt | Liquid chlorine | |
|---|---|---|
| Install | $1,800 | $0 |
| Consumables, 10 seasons | $3,750 | $5,100 |
| Cell replacements (2) | $1,400 | — |
| Total | $6,950 | $5,100 |
Over ten years, on chemicals alone, salt costs more. The saving on chlorine does not cover the equipment.
That flips on a larger pool. At 35,000 gallons the chlorine line roughly doubles while the cell cost does not, and salt comes out ahead by year seven or eight. Below about 15,000 gallons salt never pays back on money.
So why do people convert
Because money is not why anyone does this.
Water feel. A salt pool runs at 3,000–3,500 ppm salt — about a tenth of seawater, roughly the salinity of a tear. It feels softer, and it does not produce the smell and eye sting people associate with chlorine. That smell is chloramines, which is a chlorine-management problem in either pool, but a salt cell's continuous low-level dosing genuinely produces fewer of them.
Consistency. The cell doses continuously while the pump runs, instead of a slug of chlorine every few days. Fewer swings, less algae opportunity.
Not handling chemicals. No jugs, no lifting, no storage, no spills on the deck.
Those are good reasons. They are just not financial ones, and a comparison presented as a saving is being presented wrongly.
What a salt pool does not exempt you from
Testing. A salt pool needs pH, alkalinity, calcium, CYA and salt tested on the same schedule, and the order of adjustment is unchanged — chemistry sequence still matters.
Stabilizer. An outdoor salt pool needs CYA exactly like any other, at 60–80 ppm for salt systems, or the cell spends its life replacing chlorine the sun destroys.
Shocking. A salt pool with a real problem gets shocked with liquid chlorine like any other. The "super chlorinate" setting on the cell is not a shock; it produces a few ppm over 24 hours, and a green pool needs considerably more, considerably faster.
The corrosion question
Salt at 3,200 ppm is corrosive to some materials — natural stone coping, some soft masonry, and untreated metal near the water. Modern equipment is built for it, and the practical risk is with older heaters and with decking material rather than with the pool shell.
The honest summary: convert for the water, not for the invoice, and budget the cell from day one.