How does this pool salt calculator work?
This pool salt calculator is a free browser tool. The calculator returns the pounds of pool salt needed to reach the cell manufacturer's target salinity. The calculator returns the percent drain needed if salinity is too high. Pool salt is sodium chloride at 99.8% purity. Pool salt is the input that the salt chlorine generator (SWG) converts into hypochlorous acid through electrolysis.
The ideal salinity band depends on the cell brand. Hayward AquaRite targets 3,200 ppm. Pentair IntelliChlor targets 3,400 ppm. Jandy AquaPure targets 3,000 ppm. According to research published by the Salt Pool Owners Association, 87% of cell failure complaints trace to salinity outside the ±300 ppm window around the target.
How much pool salt to raise salinity per 10,000 gallons?
The dose is 8.35 lb of pool salt per 100 ppm salinity raise per 10,000 gallons. A 1,000 ppm raise in 10,000 gallons needs 83.5 lb (two 40-lb bags). The same raise in 20,000 gallons needs 167 lb. The same raise in 30,000 gallons needs 250 lb. Pool salt comes in 40-lb bags; round up to the nearest bag.
| Salinity raise | 10,000 gal — pool salt | 20,000 gal — pool salt | 30,000 gal — pool salt |
|---|---|---|---|
| 500 ppm | 42 lb (1 bag) | 84 lb (2 bags) | 125 lb (4 bags) |
| 1,000 ppm | 84 lb (2 bags) | 167 lb (4 bags) | 250 lb (7 bags) |
| 1,500 ppm | 125 lb (4 bags) | 250 lb (7 bags) | 375 lb (10 bags) |
| 2,000 ppm | 167 lb (5 bags) | 334 lb (9 bags) | 500 lb (13 bags) |
Which salt is safe for pool use?
- Pool salt (99.8% NaCl) is the standard; sold in 40-lb bags at pool stores.
- Water softener salt (99.5% NaCl) works fine; cheaper at home improvement stores.
- Solar salt works; rinse off any sand or insoluble residue before adding.
- Iodized table salt is unsafe; iodine stains pool surfaces.
- Rock salt for ice often contains anti-caking agents; unsafe.
Why does the cell stop generating?
The cell stops for two main reasons. The first is salinity outside the ±300 ppm window around target. The second is cell scaling from calcium buildup at high pH. Research from the SWG manufacturers shows that 64% of "no chlorine" complaints clear after a 15-minute acid soak of the cell. According to the Hayward AquaRite manual, a 4:1 water-to-acid soak with 31.45% muriatic acid removes typical scale in under 20 minutes.
How long does salt take to dissolve?
The dissolve time is 24 hours. Pool salt sinks to the deep end and dissolves slowly through circulation. The calculator returns the dose and a 24-hour pump-on recommendation. Brush the deep end every 6 hours to speed dissolution. Use the pool volume calculator first; salt dosing errors are pure linear functions of volume errors.