Salt Water Pool Calculator
Calculate how much salt to add to reach your ideal salinity level, with bag count and cost estimate.
Pool Details
gallons
ppm
ppm
Current Salt Level
0
1000
2000
3200
4500
6000
Salt to Add
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40 lb Bags Needed
Estimated Cost
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New Salt Level (after adding)
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After-Rain Dilution Calculator
Heavy rain dilutes pool salt. Estimate how much salt you need to restore level after rainfall.
in
sq ft
Salt Water Pool Basics
A saltwater pool uses a salt-chlorine generator (SWG) that converts dissolved salt (sodium chloride) into chlorine through electrolysis. The pool still uses chlorine — it's just generated on-site rather than added manually.
| Salt Level | Condition | Action |
|---|---|---|
| Below 2,000 ppm | Too low — SWG won't function | Add salt immediately |
| 2,700–3,400 ppm | Ideal operating range | Maintain level |
| 3,500–4,000 ppm | Slightly high | Dilute with fresh water |
| Above 4,500 ppm | Too high — may damage equipment | Drain and dilute |
Formula: lbs of salt = (target ppm − current ppm) × pool gallons ÷ 1,000,000 × 8.34 (lbs per gallon of water).
Salt does not evaporate. The only ways to lose salt are through backwashing, splashout, overflow from rain, or draining. Test salt levels monthly and after heavy rain.