Calculate the missing salt mass
Salt product in kg = pool liters x positive salt increase in ppm / 1,000,000 / purity fraction. For dilute pool water, ppm is approximated as milligrams per liter. This neglects the small change in solution volume after adding salt.
A 10,000-liter pool increasing from 1,000 to 3,000 ppm needs 20 kg of pure sodium chloride. At 99.8% purity, the product quantity is about 20.04 kg. Those levels demonstrate the arithmetic; your generator determines the operating range.
Find your salt target in the generator manual
Use the operating salt range in your generator’s manual. Different models need different levels, so check yours before adding salt.
Resolve a large disagreement between a generator display and an independent salinity test before adding more. Salt must dissolve and mix before a representative retest; follow the equipment instructions for circulation and generator operation during addition.
When the current reading is higher
Add no salt if the current reading is already at or above your target. If it is outside your generator’s range, check the manual for dilution guidance. Get advice before draining an inground pool; groundwater can lift an empty shell.
Add, circulate, then retest
Follow the product label for application and mixing time, then retest before adding more. Keep chemicals separate: never mix chlorine with acid or other chemicals.
Common questions
Is pool salt the same as chlorine?
No. Salt is the feedstock for a salt chlorine generator. Adding salt alone does not establish a free-chlorine residual.
Why does purity change the dose?
A bag with less sodium chloride per unit weight needs more total product to supply the same sodium chloride mass. Use a salt product accepted by the generator manufacturer.
Sources & calculation notes
Check the original source for product-specific instructions and current details.
- Taylor: Complete kit instructions #5165, acid/base demand and treatment-table methodChecked 2026-10-27
- NIST: SI units of volumeChecked 2026-10-27