Each generator maker names its own target, and they differ more than most owners expect, so the calculator uses the level in your maker's manual. If you do not know your pool's volume, the pool volume calculator works it out from its size.
How to use this calculator
- Enter the pool volume in gallons.
- Test the water and enter the salt reading. For a pool just filled with fresh water, leave it at zero.
- Pick your generator, or choose Other and type the target from its manual.
- Add the salt as the steps below explain, then test again after it has circulated.
Worked examples
A new saltwater pool
Pool volume: 15,000 · Salt now: 0 ppm · Salt chlorine generator: Hayward AquaRite
- Salt to add
- 400 lb
- 40 lb bags of pool salt
- 11
- Target
- 3,200 ppm
Topping up after rain
Pool volume: 20,000 · Salt now: 2,800 ppm · Salt chlorine generator: Hayward AquaRite
- Salt to add
- 67 lb
- 40 lb bags of pool salt
- 2
- Target
- 3,200 ppm
A Pentair system
Pool volume: 25,000 · Salt now: 3,000 ppm · Salt chlorine generator: Pentair IntelliChlor
- Salt to add
- 125 lb
- 40 lb bags of pool salt
- 4
- Target
- 3,600 ppm
Salt too high
Pool volume: 18,000 · Salt now: 4,600 ppm · Salt chlorine generator: Hayward AquaRite
- Water to drain and refill
- 5,478 US gallons
- Target
- 3,200 ppm
- Share of the pool
- 30.4%
How much salt a pool needs
Salt is measured in parts per million by weight, and a gallon of water weighs 8.34 lb per US gallon. So the pounds to add are the gallons times that weight times the rise in ppm, divided by a million. Pool salt usually comes in bags of 40 lb.
Salt does not evaporate or get used up by the generator. It leaves only with water that splashes out, backwashes or overflows after rain, which is why a pool needs a top-up now and then and why the only way to lower salt is to drain part of the water and refill it.
Target salt levels by generator
- Hayward AquaRite: 3,200 ppm is optimal, within 2,700 to 3,400 ppm.
- Pentair IntelliChlor: 3,600 to 4,500 ppm, ideally the low end. It turns off below 2,600 ppm.
- Jandy AquaPure Ei: keep it within 4,000 to 4,500 ppm.
- Earlier Jandy AquaPure models: 3,000 to 3,500 ppm.
- Most people start to taste salt at about 3,500 to 4,000 ppm.
How to add salt
- Use pool salt, at least 99.8 percent pure sodium chloride: no rock salt, iodized salt or salt with anti-caking agents.
- With the pump running, pour it around the edge of the pool, not into the skimmer, and brush it so it dissolves. Jandy says to switch the generator off while the salt dissolves.
- Let the pump run for 24 hours before you test again: readings taken earlier are not reliable.
- On new plaster, wait before adding salt; Jandy says 30 days.
Common questions
How much salt do I put in my pool?
Multiply the gallons by 8.34 lb per US gallon and by the rise in ppm you need, then divide by a million: that is the pounds of salt. The calculator does it for your pool and generator.
How many bags of salt for a new pool?
It depends on the gallons and your generator's target. Enter zero as the salt reading for fresh water, and the calculator counts the 40 lb bags.
What should the salt level be in my pool?
Whatever your generator's manual says: Hayward aims for 3,200 ppm, Pentair for 3,600 to 4,500 ppm and the Jandy AquaPure Ei for 4,000 to 4,500 ppm.
How do I lower the salt in my pool?
Drain part of the water and refill with fresh water. Salt does not evaporate, so time alone will not bring it down; the calculator shows how much to drain.
How long after adding salt can I test it?
Run the pump for 24 hours, so the salt dissolves and mixes, before you trust a new reading.