How the salt dose is worked out
pounds of salt = (target ppm − current ppm) × gallons ÷ 120,000
One pound of salt in 10,000 gallons raises the level by about 12 ppm. A 20,000-gallon pool going from 0 to 3,200 ppm needs 533 lb, which is 14 bags of 40 lb. Add the bags along the shallow end with the pump running, brush the piles, and leave the chlorinator off for 24 hours until the salt has dissolved and circulated. Then retest and top up; it is far easier to add than to remove.
Going down instead of up
If the level is too high, the only way down is dilution: drain part of the pool and refill. To drop from 4,000 to 3,200 ppm you replace 20 % of the water. The fill time calculator tells you how long that takes.
Factor source: Trouble Free Pool, Pool School, "Salt" (1 lb per 10,000 gal ≈ 12 ppm); salt chlorinator manuals (Hayward, Pentair) for target ranges. Read October 18, 2026.
Frequently asked questions
How many pounds of salt do you need for a 15,000 gallon pool?
From fresh water to 3,200 ppm: 400 lb, which is ten 40 lb bags. From 2,000 to 3,200 ppm: 150 lb, four bags. The formula is (target − current) × gallons ÷ 120,000.
How many 40 lb bags of salt for a 10,000 gallon pool?
Seven bags from fresh water to 3,200 ppm (267 lb). If the pool already reads 2,500 ppm, two bags (58 lb) bring it to target. Always test first; salt stays in the water and only leaves by splash-out, backwashing and rain dilution.
What is a good salt level for a 10,000 gallon pool?
The level your chlorinator asks for, usually between 2,700 and 3,400 ppm, with 3,200 a common target. Pool size does not change the target ppm, only the pounds needed to reach it.
What are the symptoms of too much salt in a pool?
The chlorinator shows a high-salt warning or shuts off, the water tastes noticeably salty above about 5,000 ppm, and metal fittings corrode faster. The only fix is to drain part of the water and refill; the calculator shows the share to replace.
How do I add salt to my pool?
Pour the bags into the shallow end with the pump running and the chlorinator switched off, brush any piles until they dissolve, run the pump for 24 hours, then retest and switch the cell back on. Use pool-grade or water-softener salt without additives.