Enter your pool's gallons, your salt cell and today's salt reading. You get the pounds of salt to reach the cell maker's own target, in bags, and the chlorine or shock for your gallons from the product's label.
Your pool's salt and chlorine
Add 267 lb of pool salt to your 10,000 gallonsHayward AquaRite's 3,200 ppm, from 0 · 7 bags of 40 lb · 64 oz to 1 gal of 10% liquid chlorine to shock
Quick answer: salt-cell makers set their own target. Hayward AquaRite: 3,200 ppm (ideal 2,700–3,400), which takes 267 lb of salt for 10,000 gallons starting from none. Pentair IntelliChlor: 3,600 ppm, which takes 300 lb. Test first and add only the difference: pounds = gallons × (target − reading) × 8.345 ÷ 1,000,000. For chlorine, follow the label: a 10% liquid chlorine label shocks with 64 to 128 oz per 10,000 gallons.
How to use the pool salt calculator
- Enter your pool’s gallons, or its shape and size: the calculator uses Hayward’s own formulas (length × width × average depth × 7.5 for a rectangle, diameter × diameter × depth × 5.9 round, × 6.7 oval).
- Pick your salt cell and enter today’s salt reading in ppm, from test strips, a meter or the cell’s display. Enter 0 for a new salt pool.
- Pick the chlorine you use and what for. You get the salt to add in pounds and 40 lb bags, or the share of water to replace if it is too salty, and the chlorine dose from the label.
Don’t know your gallons? The above-ground pool size calculator gives them from the makers’ own capacity tables.
The rules, and where they come from
Hayward. Its AquaRite manual: “The ideal salt level is between 2700-3400 ppm (parts per million) with 3200 ppm being optimal.” “A low salt level will reduce the efficiency of the AquaRite”, and a high one “can cause the AquaRite to shutdown”; salt “will begin to be tasted at a level of about 3500-4000 ppm”.
Pentair. Its IntelliChlor guide (Rev. R, 2023): “3600 ppm of salt is recommended for optimum water condition.” Below 2,600 ppm the unit turns off; “above 4500 ppm may cause excessive corrosion or deterioration to pool equipment”.
One sum. Both charts are the same arithmetic: a gallon of water weighs about 8.345 lb, and a part per million is a millionth of it. Pounds = gallons × (target − reading) × 8.345 ÷ 1,000,000. It matches Hayward’s chart to within two pounds and Pentair’s to within a tenth.
Too salty. Hayward: “The only way to lower the salt concentration is to partially drain the pool and refill with fresh water.” Replacing a share of the water lowers the salt by the same share.
Chlorine. The doses are the labels’. Champion’s EPA-registered 10% liquid chlorine: “superchlorinate with 64 to 128 oz. of product for each 10,000 gallons of water to yield 5 to 10 PPM available chlorine”. HTH Shock Advanced: “Add 1 lb (1 bag) of this product per 13,500 gallons of pool water.”
Hayward’s chart: pounds of salt for 3,200 ppm
| Salt now, ppm | 8,000 gal | 10,000 gal | 16,000 gal | 20,000 gal | 30,000 gal | 40,000 gal |
|---|---|---|---|---|---|---|
| 0 | 213 | 267 | 427 | 533 | 800 | 1,067 |
| 1,000 | 147 | 183 | 293 | 367 | 550 | 733 |
| 2,000 | 80 | 100 | 160 | 200 | 300 | 400 |
| 2,400 | 53 | 67 | 107 | 133 | 200 | 267 |
| 2,800 | 27 | 33 | 53 | 67 | 100 | 133 |
From the AquaRite 900 manual’s chart (8,000 to 40,000 gallons). At 3,200 Hayward marks “Ideal”, 3,400 “OK”, 3,600 and up “Dilute”.
Pentair’s table: pounds of salt for 3,600 ppm
| Salt now, ppm | 10,000 gal | 20,000 gal | 30,000 gal | 40,000 gal | 60,000 gal |
|---|---|---|---|---|---|
| 0 | 300 | 601 | 901 | 1,202 | 1,803 |
| 1,000 | 217 | 434 | 651 | 868 | 1,302 |
| 2,000 | 134 | 267 | 401 | 534 | 801 |
| 2,500 | 92 | 184 | 275 | 367 | 551 |
| 3,000 | 50 | 100 | 150 | 200 | 300 |
From the IntelliChlor guide’s Table 2 (10,000 to 60,000 gallons), rounded to the pound.
Chlorine and shock, by the label
| Product | To shock | To keep it up | Swim again |
|---|---|---|---|
| 10% liquid chlorine (EPA Reg. 55852-2) | 64–128 oz per 10,000 gallons, for 5–10 ppm | 13 oz per 10,000 gallons, for 0.6–1.0 ppm | below 4.0 ppm |
| 12.5% liquid chlorine (EPA Reg. 55852-3) | 52–104 oz per 10,000 gallons, for 5–10 ppm | 11 oz per 10,000 gallons, for 0.6–1.0 ppm | below 4.0 ppm |
| HTH Shock Ultra (calcium hypochlorite 56%) | 1 lb bag per 16,750 gallons; double for cloudy water | — | back to 1–4 ppm |
| HTH Shock Advanced (calcium hypochlorite 56.44%) | 1 lb bag per 13,500 gallons; double for cloudy water | — | back to 1–4 ppm |
The liquid chlorine rows are Champion’s EPA-registered labels; the HTH rows are HTH’s own directions. Other brands differ: use your product’s label.
Worked examples
Add 267 lb of pool salt to your 10,000 gallons: a new Hayward salt pool. That is 7 bags of 40 lb, brushed in with the pump running.
Add 67 lb of pool salt to your 10,000 gallons: topping up after rain and backwashing. Hayward’s chart prints 67 lb for 10,000 gallons at 2,400 ppm.
Add 184 lb of pool salt to your 20,000 gallons: Pentair’s 3,600 ppm target. Its table prints 183.60 lb.
Too salty: replace about 24% of your 10,000 gallons with fresh water: over Hayward’s 3,400 ppm. Drain about a quarter and refill with fresh water.
Common mistakes
- Adding salt without testing. Hayward: “there may already be salt in your pool from prolonged use of chlorine”. Add only the difference.
- Using one maker’s target for another’s cell. Hayward aims at 3,200 ppm, Pentair at 3,600. Check your own cell.
- The wrong salt. Hayward: sodium chloride “greater than 99% pure”; not rock salt, iodized salt or salt with anti-caking additives.
- Trusting one reading. Pentair: readings vary between strips, meters and titration, and its sensor is within ±500 ppm.
- Swimming too soon after a shock. The liquid chlorine labels: “Do not enter pool until the chlorine residual drops below 4.0 PPM.”
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Pool salt and chlorine questions
How much salt do I put in my pool?
Enough to reach your cell maker’s target: 3,200 ppm for Hayward, 3,600 for Pentair. From no salt, that is 267 lb (Hayward) or 300 lb (Pentair) for 10,000 gallons. Test first and add the difference.
How do I use a pool salt calculator?
Enter the gallons, the target and today’s reading. Pounds = gallons × (target − reading) × 8.345 ÷ 1,000,000, which is the arithmetic behind both makers’ charts.
What is a pool shock calculator for?
The dose for your gallons from your product’s label. HTH Shock Ultra: 1 bag per 16,750 gallons; HTH Shock Advanced: 1 bag per 13,500 gallons; double for cloudy water.
How much chlorine do I add to my pool?
Champion’s 10% liquid chlorine label: 13 oz per 10,000 gallons to keep 0.6 to 1.0 ppm, and 64 to 128 oz per 10,000 gallons to shock to 5 to 10 ppm.
How much liquid chlorine do I add to my pool?
For 10% liquid chlorine, 64 to 128 oz per 10,000 gallons to shock; for 12.5%, 52 to 104 oz. A 20,000-gallon pool takes twice that.
How much shock do I add to my pool?
One HTH Shock Advanced bag per 13,500 gallons, so 2 bags for 20,000 gallons, and double that for cloudy water or early algae. HTH says to use the whole bag once opened.
What if my pool has too much salt?
Drain part of it and refill with fresh water, as Hayward says. Replacing a quarter of the water lowers the salt by a quarter.