Pool salt calculator
A salt cell is a chlorine factory with one raw material. Feed it too little and it throttles; feed it too much and it corrodes the ladder and voids the warranty. This works out the bags — and, when someone has over-salted, the only fix there is.
Salt cells state their own target — most sit between 2,700 and 3,400 ppm. Read your cell's plate before you trust a generic number.
Add salt
147lb
3.7 × 40 lb bags. Broadcast over the deep end with the pump running, brush, and give it 24 hours before you trust the cell's own reading.
Salinity after the correction
3,200ppm
What it measures
Salinity is just mass over volume: 1 ppm is 1 milligram of salt per litre of water. A 10,000 gallon pool holds 37,854 litres, so lifting it 1,000 ppm takes 37.9 kg — 83 lb, two bags and a bit. That is the whole calculation; the calculator only saves you the arithmetic and the unit conversions.
What it cannot do is tell you your cell's target. Manufacturers publish different numbers and the cell's own display is calibrated against its own spec, so read the plate on the cell body and type that in.
Worked example
| Step | Working | Result |
|---|---|---|
| Gap to close | 3,200 − 2,400 ppm | 800 ppm |
| Litres in the pool | 22,000 gal × 3.785 | 83,279 L |
| Salt needed | 83,279 × 800 mg | 66.6 kg |
| In pounds | 66.6 × 2.205 | 147 lb |
| Bags | 147 ÷ 40 | 3.7 |
Buy four bags, add three
Salt is cheap and irreversible. Add most of the calculated amount, brush it off the floor, wait a full day and re-test before you open the last bag. Every tech has met a pool someone salted to 5,000 ppm from a single confident pour.
Dosage notes
Use pool-grade sodium chloride, not water-softener pellets with anti-caking additives. Broadcast across the deep end with the pump on circulate, then brush the pile — salt that sits on a vinyl floor for hours can bleach it. Salt pools also climb in pH as the cell runs, so pair this with the acid demand calculator and expect to add acid more often than a tablet pool.