A salt pool is still a chlorine pool — the cell just makes the chlorine.

A salt cell— sometimes called a salt chlorine generator, or SWG — is a small electrically charged chamber plumbed into the return line after the pump and filter. As pool water passes through, a low DC voltage across titanium plates converts the dissolved salt(sodium chloride) into chlorine gas in the water. That chlorine immediately becomes hypochlorous acid — the same sanitizer a chlorinated pool gets from pucks, liquid shock, or cal-hypo.

There is no delivery truck, no storage closet full of buckets, no weekly task of hauling chlorine to the pool. The cell runs whenever the pump runs, and free chlorine appears continuously across the day. The trade-off is mechanical: a salt cell needs water with the right salt level, a clean plate surface, and a stabilizer band that keeps the generated chlorine from burning off in the sun.

A salt pool is not a chlorine-free pool. The chlorine concentration in the water is the same shape of thing (free chlorine, measured in ppm), and the recommendations for pH, total alkalinity, and calcium hardness are identical. The salt itself is just the feedstock.

The recommended range for a salt pool is 2700 – 3400 ppm. Most cells run happiest around the upper-middle of that band — a cell set to produce 50% output will reach steady-state chlorine faster when salt sits at 3200 than when it sits at 2700. The salt pill ClearDose renders is color-coded like the rest:

If the reading is low, the pool will probably tell you itself before the app does: the cell stops producing chlorine and the controller lights a “low salt” or “check salt” warning. A low reading is almost never a salt-cell failure — it's splash-out, a backwash that went too long, a heavy rain, or a leak. Add pool-grade salt directly to the water (never table salt) and re-test after a full pump cycle.

If the reading is high, it usually means salt has been added on top of an existing reading without re-testing first. Above ~4000 ppm, salt becomes corrosive at metal fittings and can shorten cell life; most manufacturers explicitly warn against going well over the upper end of the band. The fix in the short term is patience (salt will drop with rain and splash-out over time); the fix on a faster timeline is a partial drain and refill.

Top up when:the salt reading sits below 2700 ppm and the rest of the chemistry is fine. The pool is losing salt to splash-out, backwash, or a wet bather day, and the fix is to add pool-grade salt directly to the deep end with the pump running, then re-test tomorrow. Most pools will want a top-up once or twice a season — more after heavy rains, less in a covered or lightly-used pool.

Drain and refill when: the reading you actually need to fix is CYA, because CYA goes up but does not come down. Every stabilized chlorine product — tabs, sticks, the chlorine puck the cell optionally runs on — adds CYA. After two or three seasons of trichlor tabs, many salt pools see CYA climb past 100 ppm even when the salt reading sits comfortably in range. At that point raising the salt with another top-up worsens a pool whose real problem is locked-up chlorine; the move is to drain (partially or fully, depending on the target) and refill.

The simplest decision tree: low salt, fine everything else → top up with pool-grade salt. low salt, high CYA → drain and refill, then re-balance from a known-zero starting point. high salt, fine everything else → leave it; rain and splash-out will bring it down. high salt, high CYA → drain and refill. Reverse-osmosis treatment can pull CYA down without draining, where the service is available and the budget tolerates it.

Salt cells scale. Calcium drops out of pool water as calcium hardnesssits at the high end of its range and water temperatures rise, and it tends to land on the warmest surface in the loop — which is the inside of the cell, on the plates. A scaled cell produces less chlorine per hour of pump time, runs hotter, draws more current, and dies younger than a clean one.

The standard cadence is to inspect the cell visually every couple of months and clean it whenever there is visible white scale on the plates. Most pool owners end up cleaning once or twice a season; pools with hard fill water or calcium hardness sitting at the top of the range may need to clean monthly in peak summer.

Cleaning is a mild-acid wash, not a heavy-handed scrub: turn the pump and cell off, remove the cell, rinse loose debris with a hose, then soak in a 4:1 water-to-muriatic solution (or a purpose-made cell-cleaning product) until the scale dissolves — usually under fifteen minutes. Never use a wire brush or a metal scraper on the plates, and always confirm the concentration on your acid jug's label rather than relying on a universal ratio.

CYA is the lever most owners miss. When CYA climbs past 80–100 ppm, scale tends to come on faster because the cell has to run harder to keep free chlorine available against the locked-up stabilizer. Holding CYA inside 30 – 50 ppm is the cheapest way to slow scale buildup and extend the interval between cleanings.

In a traditionally-chlorinated pool, the standard shock treatment resets the system: you dump a big slug of chlorine into the water, the level spikes, the pool is sanitized — and any excess CYA-built-up lockup gets unwound. A salt pool has no equivalent. The cell makes chlorine continuously at whatever output percentage it's set to, and the practical ceiling on what it can do is fixed by the controller's hardware. There is no “shock to reset” unless you add a manual dose on purpose.

That makes CYA harder to manage, not easier. CYA binds to free chlorine and reduces its effective sanitizing power: at 30 ppm CYA the relationship is mild and useful (sun protection); at 80+ ppmCYA, free chlorine is present on the test strip but largely unavailable, so algae gain a foothold even when the readings look fine. In a salt pool, the cost of letting CYA drift up is paid in a slowly greening pool that no amount of cell output can rescue — because the controller simply cannot produce enough chlorine to overcome a high CYA reading.

The recommended band is the same as for a chlorinated pool — 30 – 50 ppm— and the rule for moving it down is the same too: drain and refill. There is no shortcut. Tabs and stabilized shock add to the problem; liquid chlorine and a saltwater Liquidator / non-stabilized shock do not, but the easiest long-run defense is to keep CYA in the band in the first place, which in a salt pool means being deliberate about which chlorine products touch the water at all.