Saltwater Pool Conversion Calculator
| Pool gallons | Salt pounds | 40-lb bags | SWG payback at $40/mo |
|---|---|---|---|
| 10,000 | ~270 lb | 7 bags | ~2.5 seasons ($1,500 SWG) |
| 15,000 | ~400 lb | 10 bags | ~3 seasons ($1,500 SWG) |
| 25,000 | ~670 lb | 17 bags | ~3.5 seasons ($1,800 SWG) |
The salt math is one formula: gallons times 8.34 pounds per gallon, times the target 3,200 parts per million, divided by a million - which is why a 15,000-gallon pool wants about 400 pounds of salt, ten 40-pound bags dumped in a day with the pump running.
Bottom line: the saltwater generator costs 1,000 to 2,500 dollars installed, replaces 30 to 50 dollars a month of chlorine tablets, and pays back in two to four seasons for most pools - with the water that stops smelling like a hotel pool as the bonus the spreadsheet cannot price.
The honest part: saltwater pools are still chlorine pools - the generator makes the chlorine from the salt - and the conversion adds two new maintenance lines: the cell that needs acid cleaning every few months and the 3-to-5-year cell replacement that runs 300 to 800 dollars. The payback math should count the cell, and usually still wins.
How to use
- Enter pool gallons and read the salt pounds and bag count to reach 3,200 ppm - poured with the pump running, brushed, and retested after 24 hours of dissolving.
- Enter your monthly chlorine-tab spend to see the saltwater generator payback, counting the tabs, the floater and the shock that the cell replaces.
- Check the cell-replacement reserve: 300 to 800 dollars every three to five years is the honest line that keeps the payback arithmetic true.
Frequently asked questions
How much salt does a saltwater pool need?
About 3,200 parts per million is the target, which works out to roughly 27 pounds of salt per 1,000 gallons - a 15,000-gallon pool wants about 400 pounds, or ten 40-pound bags. Existing salt in the water counts, so test before the first pour, and the salt goes in with the pump running and gets brushed until it dissolves.
Is a saltwater pool cheaper than chlorine tablets?
After the conversion, yes - a generator's salt and electricity run 15 to 25 dollars a month against 30 to 50 of tabs and shock. Before it, no: the 1,000-to-2,500-dollar system and the 300-to-800-dollar cell every few years front-load the costs, and the payback lands in two to four seasons at typical tablet spending.
Is a saltwater pool actually chlorine-free?
No - the generator makes pure chlorine from the salt through electrolysis, which is why the water still tests the same way. What changes is the form: steady low-level chlorine instead of weekly tablet spikes, no stored-chlorine smell, and the softer feel that swimmers notice on skin and eyes. The chemistry tests and the pH management continue exactly as before.
Can any pool be converted to saltwater?
Almost any, with the honest exceptions living in the equipment: older pools with galvanized or natural-copper components corrode in salt water, and some older heaters and pumps want replacement parts first. Plaster finishes handle salt fine; some stone copings etch slowly. A pool pro checks the equipment list before the first bag goes in - the conversion is a system change, not a chemical one.