Calculate salt requirements for your saltwater pool. Maintain the correct salinity for your chlorine generator to ensure consistent sanitization. Accurate salt levels are vital for the health of your salt cell and the continuous production of chlorine for a clear pool.
Enter your pool volume and your current salinity reading in parts per million (ppm), then your target. A saltwater pool does not skip chlorine; its salt-chlorine generator electrolyzes dissolved salt into chlorine, so the cell needs the salinity its manufacturer specifies, commonly 2,700-3,500 ppm with about 3,200 ppm as a typical sweet spot. Read your unit's manual for the exact figure and enter that as the target. If you are starting from plain fill water, current salinity is often 0-500 ppm; for an established pool, take a fresh reading because rain, splash-out and backwashing all dilute salt over time. The calculator raises salinity by dosing pool-grade sodium chloride (NaCl). Because salt does not evaporate and is not consumed by chlorine generation, you only add to top up losses, usually once or twice a season rather than weekly.
Method: it takes about 8.35 lb of salt per 1,000 gallons to raise salinity by 1,000 ppm (because a gallon of water weighs 8.34 lb, so 1,000 ppm equals that mass); in metric terms about 1 kg per 1,000 liters per 1,000 ppm. Pounds = volume(gal) / 1000 x (ppm_increase / 1000) x 8.35. Worked example: a 12,000 gal (45,400 L) pool reads 2,200 ppm and your cell wants 3,200 ppm, a 1,000 ppm rise. 12,000 / 1000 x 1.0 x 8.35 = 100 lb of salt, about 45 kg, or roughly two and a half 40-lb bags. If salinity is already near target, add conservatively and in halves: raising salt is easy but lowering it requires draining and refilling.
Accuracy matters because over-salting can only be corrected by dilution, wasting water, while under-salting drops the cell into low-output or no-chlorine mode and can let algae take hold. Use only high-purity (99%+) evaporated, granulated pool salt; rock salt and water-softener pellets carry impurities, anti-caking agents or iron that stain surfaces and shorten cell life. Turn the generator off, broadcast salt across the deep end with the pump running on circulate, and brush it across the floor so it dissolves rather than piling up. Wait 24 hours of full circulation before retesting and before re-enabling the cell, since an early reading reads low. Cold water also slows dissolution. Verify against your cell's own salinity display, but trust an independent test if the two disagree, and recheck whenever you add significant fresh water.
Most salt systems require a salinity level between 2,700 and 3,500 ppm. Check your specific manufacturer's manual for the ideal target for your model.
No. Only use high-purity (99%+) evaporated granulated salt designed for pools. Impurities in cheaper salts can stain your pool surfaces or damage the salt cell.
Broadcast the salt evenly across the pool surface with the pump running; do not pour it into the skimmer. Brush any piles off the floor so it does not sit on the surface, then let it circulate for 24-48 hours before testing the salinity and before turning the salt cell back on.
No. Salt only leaves the pool through splash-out or backwashing. It does not evaporate. You typically only need to top up your salt once or twice a season.
A salt chlorine generator (SWG) passes the pool water through an electrolytic cell that splits dissolved salt (NaCl) into chlorine (hypochlorous acid), which sanitizes the water; the chlorine then reverts to salt, so the same salt is reused in a continuous cycle. You only top up salt to replace what is lost to splash-out and backwashing.
It depends on your pool volume and how far your current salinity is from the target, which is usually 2,700-3,400 ppm for most salt chlorine generators. About 8.35 lb of salt per 1,000 gallons raises salinity by 1,000 ppm, so a typical 40-lb bag treats a known volume — enter your numbers above and the calculator converts the result into pounds, kilograms, and the approximate number of 40-lb bags.