Adding salt to a saltwater pool is a simple job, but doing it wrong — using the wrong type of salt, adding too much at once, or pouring it the wrong place — can damage your salt cell, throw off chemistry, and force a full partial-drain to recover. This tutorial walks through the right way to add and dial in salt for a Hayward AquaRite or any other residential salt chlorinator.
How much salt your pool needs
Most residential salt chlorine generators target 3,000–3,400 ppm. The math:
- Each pound of pool salt added to 1,000 gallons of water raises salinity by roughly 120 ppm.
- For a 20,000-gallon pool starting at zero salt, you need about 500 lb (10 bags of 40 lb each) to hit 3,000 ppm.
- If you’re topping up after backwashing or splash-out, you usually need 25–75 lb to bump from a 2,800 ppm reading back to target.
Use a pool-volume calculator to confirm your exact gallons before buying salt — estimating is the most common reason owners over- or under-dose.
The right kind of salt
Use only pool-grade salt: high-purity (99%+) sodium chloride, evaporated or solar-dried, with no yellow-prussiate-of-soda anti-caking agents. Water softener salt usually works but is sometimes labeled with rust inhibitors that stain plaster. Never use rock salt (impurities) or table salt (iodized, with anti-caking agents that cloud pool water). Most home improvement stores carry “pool salt” clearly labeled.
Step-by-step: adding salt to your pool
The salt cell’s built-in salinity reading is approximate and drifts over time. Use a dedicated test kit or salt strip to get an actual ppm before adding anything.
Target ppm minus current ppm = ppm to raise. Multiply by pool gallons, divide by 120,000 to get pounds of salt. Example: raise from 2,500 to 3,200 in a 20,000 gallon pool = 700 × 20,000 / 120,000 = 117 lb (round up to 120, or three 40 lb bags).
You want full circulation to dissolve salt evenly, but the cell off so it isn’t trying to electrolyze in undissolved salt water.
Do not dump it into the skimmer — undissolved salt can settle in the pump and cell. Do not dump it all in one spot — high-concentration salt brine sinks to the bottom and pits plaster. Walk around the deep end pouring slowly. Brush undissolved salt off the floor every 15 minutes for the first hour.
Salt takes a full circulation cycle (or two) to dissolve completely and mix evenly. Don’t test or turn the cell on for at least 24 hours.
If you’re within 200 ppm of target, you’re done. Turn the cell back on. If you under-shot, add more salt. If you over-shot, the only fix is partial drain and refill (or wait for evaporation and rain to dilute — can take weeks).
Common mistakes
- Adding salt with the cell on. The cell sees a localized high-salt brine and can overheat or scale.
- Trusting the cell’s built-in salinity readout. Sensors drift 200–400 ppm over time. Always confirm with a separate test.
- Over-dosing because “more chlorine production = good.” Salt above 5,000 ppm shortens cell life, corrodes coping and ladders, and is hard on swimmers. Stay in the manufacturer’s recommended range.
- Topping off pool with fresh water and not retesting salt. Evaporation concentrates salt; rainwater dilutes it. Either direction needs a retest before assuming.
Tools you’ll need at the pad
A dedicated salt test, a working salt cell, and the chemicals to keep pH where the cell likes it — that’s the full kit for a healthy saltwater pool:
Taylor K-2005 Salt Test Kit
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Hayward T-CELL-9 (up to 25,000 gal)
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Durachlor 5 Lb pH Down Reducer
Shop NowNeed help calibrating your AquaRite or sizing a new cell for your pool? PST Pool Supplies handles salt-system questions every day. Send us your pool volume and current readings and we’ll walk you through the right adjustment.