How to add salt to a pool
Start the pump first, pour the salt in, and keep it going for 24 hours. Buy salt in 40 lb bags, more than 99% pure sodium chloride, as the manual from Hayward's specifies. Pull from the main drain while it runs, says Hayward. Check the salt level a day later.
Getting it into the water
Switch the filter pump on before anything else. Pour each of the 40 lb bags straight into the pool once you've got them open.
Per Hayward, the pump should draw suction from the main drain. Keep it going a full 24 hours, which Pentair's guide calls for so the salt dilutes properly.
After that, check the salt.
Knowing when salt is needed
Put salt in once a test falls below the range your system needs. A Hayward AquaRite operates between 2700 and 3400 ppm (parts per million, the number a salt test shows), and 3200 ppm is ideal. The Pentair IntelliChlor aims for 3600 ppm; Intex and Bestway sit at 3000 ppm.
For Jandy AquaPure models, Jandy's manual calls for 3.0 to 3.5 gpl (grams per liter; 1 gpl is 1,000 ppm). Below 2.0 gpl, the cell turns itself off. With fresh plaster, give it 10 to 14 days to cure before any salt goes in.
How often it needs topping up?
Only put salt in when a test shows it's low. The chlorinator manual tells you the range you're aiming for.
Once 24 hours of pump run time has passed after each bag, test again.
The rest of your numbers
Salt is only one of the numbers your test gives you.
Look at the other readings at the same time. According to Pentair, free chlorine should sit at 2.0 to 4.0 ppm and pH ideally at 7.4 to 7.6. For outdoor pools, Hayward's AquaRite 900 calls for 30 to 50 ppm of stabilizer.
Questions people bring to the counter
What's the best way to get salt into your pool?
Get the filter pump going. Empty in 40 lb bags of sodium chloride that's over 99% pure. Have the pump draw from the main drain. Keep it running 24 hours so everything blends fully.
How can I tell if my saltwater pool needs more salt?
Match your salt test result to what the chlorinator manual says. The Hayward AquaRite aims for 3200 ppm, the Pentair IntelliChlor for 3600 ppm and CircuPool for 3500 ppm. Units from Intex, Bestway and Jandy TruClear operate at 3000 ppm.
Is it okay to put both salt and chlorine into a pool?
Yes. Even a salt pool depends on free chlorine. Per Pentair's manual, free chlorine ideally sits at 2.0 to 4.0 ppm while salt sits at 3600 ppm. For pH, Pentair's range goes from 7.2 to 7.8.
What's the count of 40lb salt bags your pool needs?
Start by testing your salt. Subtract that reading from your goal, like a Hayward target of 3200 ppm or a Pentair goal of 3600 ppm. The difference is how many ppm you're short. Next multiply your gallons by 8.34. Multiply the result by the ppm you're missing. Now divide by 1,000,000. That figure is the pounds of salt. Now divide that figure by 40. The answer is how many bags you need. Got a gpl reading instead? A reading of 1 gpl works out to 1000 ppm.