How much salt do I need for my pool?
Starting a 15,000 gallon pool from scratch calls for 400 pounds of salt to hit 3,200 ppm (parts per million, the number a salt test shows). That works out to 10 bags at 40 pounds each. Sitting at 2,400 ppm already? That leaves you 800 ppm below target. So you need 100 pounds, and CircuPool's guide offers a fast startup figure of 30 pounds for each 1,000 gallons.
How many pounds of salt each pool size takes?
Per the USGS, one gallon of fresh water tips the scale at 8.34 pounds. That figure is what converts ppm into pounds for you.
Getting to 3,200 ppm takes 26.7 pounds of salt per 1,000 gallons of water. Put another way, a 15,000 gallon pool at 0 ppm will need 400 pounds of salt.
Salt for pools is typically sold in bags of 40 to 80 pounds. Split 400 pounds into 40 pound portions and you end up with 10 bags.
The ppm your chlorinator asks for
Look up the target ppm in the chlorinator's manual ahead of any salt purchase.
Hayward calls for a range of 2,700 to 3,400 ppm. Set your sights on 3,200 ppm, while Pentair asks for 3,600 ppm.
A reading of 3,000 ppm is the shared goal across Intex, Bestway and Jandy TruClear systems. With CircuPool the target is 3,500 ppm, rising to 4,000 ppm when you own an SJ model.
Topping off salt once you've backwashed or refilled
Did a backwash drain some water? Test it. When levels fall low, bring the salt back up.
Check the water ahead of any top up. Take your current reading away from the target ppm.
Picture a 15,000 gallon pool where a backwash removes 1,500 gallons. Fresh water goes back in to replace it. Bringing that 1,500 gallons up to 3,200 ppm takes 40 pounds of salt. In other words, 1 bag at 40 pounds.
Adding the salt
Is the plaster new? Give it 10 to 14 days to cure before anything else.
Have the pump draw through the main drain. Add the salt after that.
Keep your filter pump going for 24 hours so the salt can mix in. Once that 24 hour run finishes, test the water.
Questions people bring to the counter
What's the right amount of salt for my pool?
Check the water first, then take that number away from the ppm your chlorinator aims for. Being 400 ppm under in 15,000 gallons means adding 50 pounds of salt. Put it in and let the pump run for 24 hours.
What number of 40 pound salt bags do I need?
Filling a fresh 15,000 gallon pool? Plan on 400 pounds of salt to hit 3,200 ppm. Split 400 pounds into 40 pound bags and you end up with 10 bags. Topping up from 2,400 ppm needs 100 pounds.
Is it possible to put in too much salt?
Yes, the level can climb beyond the range. Anything above 3,400 ppm sits outside Hayward's ideal range. CircuPool tells you to keep it from 3,000 to 4,000 ppm. Give it a full day of pumping, then test before you add more.
Which ppm targets do Intex and Pentair set?
The Intex range runs from 2,500 to 3,500 ppm. With Pentair, the goal is 3,600 ppm. After the salt goes in, give the pump 24 hours before testing once more. Reading still low? Add more.