How Much Salt to Add to a Swimming Pool

One of the most commonly asked questions is how much salt should I add to my swimming pool for the salt chlorinator to work correclty.

The answer will vary based on the size of the swimming pool and the existing salinity of the pool water. In most residential salt water chlorination systems you want the salt level to stay between 2800 ppm and 3800 ppm. If the salt levels are not kept within these specified ranges, most chlorinators will cease operating to prevent cell damage. Commercial applications sometimes recommend that salt levels to be kept around 5000 ppm with no damage to the chlorinator cell.

Below we have provided a chart to assist you in determining how much salt is needed to provide the correct salinity in the pool water. The first column assumes there is no salt in the pool and the second shows how much salt to add if you already have 1,500 ppm salinity in the water. Keep in mind that once the correct salinity level has been established the frequency in which salt must be added will vary based on the operating environment. Evaporation will not remove salt from the pool water and will actually raise the salinity levels until fresh water is added back to the pool.


Pool Size 3.5’ Average Depth 0-3000PPM 1500-3000 PPM
12‘x24’ 7,600 gal 180 pounds 90 pounds
15‘x30’ 11,800 gal 280 pounds 140 pounds
18‘x36’ 17,000 gal 400 pounds 200 pounds
20‘x40’ 21,000 gal 500 pounds 250 pounds
25‘x45’ 29,531 gal 700 pounds 350 pounds
30‘x50’ 39,375 gal 950 pounds 475 pound

*Every 40 pounds of salt raises salinity 500ppm per ten thousand gallons of water.