Start from the fact that settles half the argument: a saltwater pool is a chlorine pool. The cell manufactures chlorine on site by electrolysing the salt you added, rather than you carrying it home in jugs — but the water ends up sanitized by exactly the same chemical, and every rule of chlorine chemistry still applies. Anyone selling you "chlorine-free swimming" is selling you chlorine.
So the real question isn't which chemical, it's which delivery system — and that comes down to money, maintenance habits, and one chemistry difference the comparison articles routinely skip.
What actually changes, and what doesn't
| Manual chlorine | Salt system | |
|---|---|---|
| Sanitizer in the water | Identical — hypochlorous acid, from either route | |
| Testing you still do | FC, pH, TA, CH, CYA — same tests, same frequency | |
| pH, alkalinity, calcium | Same targets, same corrections | |
| How chlorine arrives | You dose it, in slugs, every few days | The cell makes it continuously while the pump runs |
| Stabilizer target | 30–50 ppm | 60–80 ppm — more sun protection needed |
| pH drift | Roughly neutral with liquid chlorine | Drifts up persistently — expect regular acid |
| Equipment that can fail | Effectively none | Cell, control board, flow switch, salt sensor |
| Effort profile | A recurring chore you can't skip | Mostly automatic, with a cell to clean and replace |
The top three rows are the ones worth internalizing: for the water itself, nothing changes. A salt pool that isn't tested goes green on the same schedule as any other.
The cost, computed instead of quoted
Published comparisons don't agree with each other. One widely-cited page puts a chlorine pool's annual chemicals at $300–800; another puts it at $950–1,350. That's a threefold spread on the central question, and neither derives it from anything. The chlorine line, at least, is genuinely calculable — a pool consumes a fairly predictable amount of chlorine per day, and the rest is arithmetic.
For a 15,000-gallon pool losing 2.5 ppm of FC a day through a seven-month season — a reasonable midsummer average — our dosing engine says you'd pour 64 gallons of 12.5% liquid chlorine:
| Sanitizer cost per season | Manual chlorine | Salt system |
|---|---|---|
| The chlorine itself | $319–$447 (64 gal at $5–7) | Made on site |
| Electricity to run the cell | — | $58 (200 W, 8 h/day, $0.17/kWh) |
| Salt top-up | — | about $40 (salt only leaves by splash-out and backwash) |
| Cell, spread over its life | — | $57–$300 ($400–900, lasting 3–7 years) |
| Season total | $319–$447 | $155–$398 |
Sanitizer only. Both systems also buy acid, stabilizer and occasional calcium, and those costs are near enough identical — a salt pool typically buys more acid, since the cell pushes pH up. Chlorine demand varies with sun, swimmers and CYA, so run your own numbers in the dosing calculator.
The honest reading: salt saves about $107 a season at the midpoint — not the multiples the marketing implies. And the range matters more than the average here. Land a cheap cell that lasts seven years and you're well ahead; land a dear one that dies in three, against chlorine bought on offer, and salt actually costs you about $79 a season more. Against an installed cost of $1,000–2,500, payback on the midpoint saving runs 9–23 seasons — which is to say the system will likely need its second cell before it has paid for its first. Buy a salt system because you'd rather not haul jugs. That's a perfectly good reason, and it's the real one.
Everything else about salt is cheap; the cell is not, and it is a consumable. Replacements run $400–900 and last three to seven years, and prices have drifted upward because the plates are coated with ruthenium and iridium — platinum-group metals now in demand for hydrogen electrolysers and semiconductors. Two things extend cell life more than anything else: oversizing it, so it runs at 40% duty rather than flat out, and keeping calcium and pH in range, since scale on the plates is what kills most cells early. The cell sizing calculator works the first one out; it's the highest-leverage decision in salt pool ownership.
The chemistry difference nobody mentions
Most comparisons don't mention stabilizer at all, and it's the one genuine chemistry change when you convert. A salt cell produces chlorine continuously and in daylight, where a manual pool gets its chlorine in an evening slug. Continuous daytime production means continuous UV exposure, so a salt pool wants a deeper stabilizer reserve to protect it:
| System | CYA target | Minimum FC | Target FC | FC as % of CYA |
|---|---|---|---|---|
| Manual chlorine | 30–50 ppm | 3 ppm | 4.5 ppm | 7.5% |
| Salt system | 60–80 ppm | 3.5 ppm | 5 ppm | 5% |
From the same target engine our calculators use. The salt column runs a lower percentage because the cell tops chlorine up all day rather than letting it sag between doses — but a higher CYA, so the absolute FC number ends up slightly higher, not lower.
Two practical consequences. If you convert, your stabilizer needs to come up — and a pool that was already high on CYA from years of tablets may need diluting rather than topping up. And the numbers you memorized stop applying: an FC of 3 that was comfortable on manual chlorine at CYA 40 is 3.5-ish territory at CYA 70, which is the floor rather than the target. The dashboard switches every target with one toggle, and the chlorine / CYA relationship explains why the ratio works this way.
"Softer water" — what's actually going on
Salt pools genuinely do feel different, and the usual explanations for it are wrong. At 3,000 ppm, a salt pool is about a tenth as salty as the sea and only just at the threshold where most people can taste it — it isn't "swimming in seawater," and the salt concentration is too low to be doing much to your skin.
What's actually different is the steadiness of the chlorine, not the salt. The stinging eyes and bleached swimsuits people associate with chlorine come from two things: chloramines, which form when chlorine is too low to break down waste properly, and the peak of a manual slug dose right after it goes in. A salt pool avoids both by holding a steady modest level all day. A manual pool dosed properly and kept at the right FC for its CYA feels much the same — the comfort comes from good chlorine management, and salt is simply a way of automating it.
Which also means the flip side is true: a neglected salt pool with a failing cell produces chloramines exactly like any other under-chlorinated pool. The system removes a chore; it doesn't remove the chemistry.
Salt at pool concentration does accelerate corrosion of some materials — but the damage usually blamed on it has more to do with splash-out landing on stone and metal, and with water chemistry, than with the salt itself. The genuine watch-list: natural stone and unsealed masonry at the waterline and on the deck, galvanized and untreated metal fixtures, ladders and handrails, heater headers on older units not rated for salt, and nearby planting where splash-out lands. The standard mitigations work: a sacrificial zinc anode, salt-rated hardware, sealing the stone, and rinsing the deck. And the biggest one is free — keep your saturation index in range, because aggressive water eats plaster and metal whether or not there's salt in it.
Converting an existing pool
Conversion is mostly a plumbing afternoon: a cell plumbed into the return line after the heater, a control box on the equipment pad, a dedicated circuit, and enough salt to reach about 3,000 ppm — roughly 9 forty-pound bags for a 15,000-gallon pool, though the salt calculator gives the exact figure from your current reading. Budget $1,000–2,500 including installation, or less if you're comfortable with the electrical work.
Two things to sort out before you buy. Check your CYA first — if years of trichlor tablets have left it at 90+, you'll want to dilute down before you start, not after. And check what your existing equipment is rated for, particularly an older heater; salt-rated heat exchangers have been standard for years, but a pre-2000 unit may not have one.
So which should you choose?
Salt suits you if the chore is what you dislike about pool ownership, you swim often enough that steady chlorine is worth automating, you have somewhere dry to keep the equipment, and you can absorb a $400–900 cell bill every few years without it stinging.
Manual chlorine suits you if your season is short (a cell you run four months a year takes a long time to pay for itself), your pool is small, you'd rather have nothing on the pad that can fail, or you like the control — liquid chlorine is the most predictable sanitizer there is, and a pool dosed properly with it is every bit as pleasant to swim in.
What shouldn't decide it: the belief that one of them isn't a chlorine pool, or that salt is meaningfully gentler on skin as a chemical matter. Both are chlorine. One of them just makes its own, and charges you a cell every few years for the privilege. If that trade appeals, the cell sizing calculator is where to start — buy it bigger than you think you need.