A "saltwater" pool still runs on chlorine — the salt-chlorine generator (SWG) just makes that chlorine from dissolved salt. Get the salinity into the cell's target band and it does the sanitizing for you. Here's how much to add and how to do it without hurting your equipment.
What level your generator wants
Most salt cells want somewhere around 3,000–3,400 ppm, but the exact number is set by your unit — check the cell or its manual (many run best near 3,200). Too low and the cell can't make chlorine and may throttle down; too high and it can throw a "high salt" fault. Our calculator defaults to a 3,200 ppm target you can change to match your cell. Salt calculator →
How much salt to add
The math the calculator uses: about 0.0834 lb of salt per 10,000 gallons raises salinity ~1 ppm. A handy rule of thumb — one 40-lb bag lifts a 10,000-gallon pool by roughly 480 ppm. So bringing a 20,000-gallon pool from 2,400 to 3,200 ppm takes about 133 lb, or four 40-lb bags. Always dose from a real test, not the cell's on-board reading. Get your exact bag count →
Which salt to buy
Use pool-grade salt that's 99%+ sodium chloride — pure, non-iodized, with no anti-caking agents and no yellow prussiate of soda. Iodized salt or anti-caking additives can stain or cloud the water. Evaporated or solar salt sold as "pool salt" is exactly right; avoid rock salt and water-softener pellets with additives.
How to add it
- Balance the water first. Get pH and alkalinity in range before you salt — it's easier now than later.
- Run the pump the whole time so the water is circulating.
- Broadcast the salt across the pool surface — never pour it through the skimmer. Sending a slug of concentrated salt through the pump, filter, and cell can damage them.
- Brush it around to dissolve any piles settling on the floor, especially in a plaster pool.
- Wait about 24 hours — with the pump running — before you test salinity or trust the generator's reading. Salt needs a turnover or two to mix evenly.
Don't overshoot
Only dilution removes excess salt — you'd have to drain and refill part of the water. So add a little less than you think, re-test after it mixes, and top up. Most cells tolerate a range, so a small overage is usually fine, but there's no chemical that takes salt back out.