Saltwater Pool Salt Calculator

Saltwater pools are still chlorine pools. The salt cell electrolyzes salt (NaCl) into hypochlorous acid — the same active sanitizer as in any chlorine pool. The water is “salty” only at fresh-tear levels (~3,200 ppm vs 35,000 ppm in the ocean). Most people barely taste it.

Standard target salinity is 3,000-3,500 ppm. Check your specific chlorinator manual:

• Hayward AquaRite: 2,700-3,400 ppm (target 3,200)
• Pentair IntelliChlor: 3,000-4,500 ppm (target 3,400)
• Jandy AquaPure: 3,000-3,500 ppm (target 3,200)
• CompuPool: 3,500-4,500 ppm (target 4,000)

The math. 1 lb of pool salt per 10,000 gallons raises salinity by ~12 ppm. Pool salt is just sodium chloride — same as table salt minus the iodine and anti-caking agents. Mineral-grade pool salt (99%+ purity) is what you want.

To go from zero to 3,200 ppm:

• 10,000 gal pool: 3,200 / 12 × 1 lb = ~267 lb
• 20,000 gal pool: ~533 lb
• 30,000 gal pool: ~800 lb

That is a lot of bags. Most pool builders salt the pool at startup; you only need to top off after rain dilutes or partial drains. Salt does not evaporate, so once you are at target, you stay there for a long time.

Worked example. 20,000 gal pool, current salinity 2,200 ppm, target 3,200.

• Raise needed = 1,000 ppm
• Salt to add = 1 lb × (1000/12) × (20,000/10,000) = 167 lb (4 standard 40-lb bags, plus a partial bag)

Pour it across the deep end with the pump running. It dissolves in 24-48 hours. Brush the floor occasionally to break up any settled piles.

When salt is too high. Only fix is partial drain and refill. There is no chemical that removes salt. Heavy rain dilutes naturally over time.

Common mistake. Adding too much salt at once because the pool store reading was off. Pool store salt tests have a typical accuracy of +/- 200 ppm. Add in stages — go to 2/3 of calculated, retest in 48 hours, then top off if needed.