If your pool uses a salt chlorine generator, keeping salinity in range is essential for stable chlorine output and long equipment life. This pool salinity calculator helps you estimate exactly how much salt to add (or how much water to replace if salinity is too high).
How this pool salinity calculator works
Salinity is measured in ppm (parts per million). A 1 ppm increase means 1 milligram of dissolved salt per liter of water. The calculator uses your pool volume and the difference between current and target salinity to estimate the required salt addition.
- If target > current: it calculates salt to add.
- If target = current: no adjustment needed.
- If target < current: it estimates partial drain/refill percentage.
It also accounts for salt purity. If your salt is 99% pure, you need slightly more product than with 100% pure salt.
Recommended pool salt levels
Saltwater pools (with SWG)
Most systems operate in the 2,700 to 3,600 ppm range, with many targeting about 3,200 ppm. Always use your chlorine generator manufacturer’s recommended setpoint.
Traditional chlorine pools
Non-salt pools can still have low natural salinity. In that case, you usually do not need to raise salt unless you are converting to a saltwater system.
Step-by-step usage
- Enter your pool volume and choose units (gallons, liters, or m³).
- Enter the salinity from a recent water test.
- Set your target salinity based on equipment specs.
- Set salt purity and bag size (optional but recommended).
- Click Calculate to get pounds, kilograms, and bag count.
Example: salt to add
Suppose you have a 15,000-gallon pool, current salinity is 2,200 ppm, and target is 3,200 ppm. The difference is 1,000 ppm. You’ll need a substantial but manageable salt addition, usually split into stages with circulation between doses for safer balancing.
After dosing, run the pump, brush to dissolve any settled salt, and retest before making a second adjustment.
What causes pool salinity to change?
- Rain and splash-out: can dilute pool water and lower salinity.
- Backwashing or leaks: remove salty water and reduce levels.
- Evaporation: water leaves, salt stays; refill practices determine net effect.
- Chemical additions: some products can slowly increase dissolved solids.
- Overdosing salt: common when volume estimates are inaccurate.
If salinity is too high
You cannot chemically remove salt from pool water. The practical method is dilution: partially drain and refill with lower-salinity water. This calculator estimates the percent and approximate volume to replace.
Tip: Replace in stages to protect surfaces and avoid structural issues, especially in high water-table areas.
Best practices for accurate salinity control
- Test with a reliable digital meter or quality drop-based kit.
- Measure pool volume as accurately as possible.
- Use plain pool salt (no additives, anti-caking agents, or yellow prussiate of soda when possible).
- Add salt in portions and circulate 12–24 hours before retesting.
- Keep records of additions and readings for easier future adjustments.
Pool salinity calculator FAQ
Can I swim right after adding salt?
Usually yes, once salt is mostly dissolved and circulated. Follow local guidance and manufacturer recommendations.
Why does my salt reading differ between test strip and controller?
Sensor calibration, water temperature, and test method quality can cause differences. Use a consistent testing method and calibrate equipment as needed.
Should I aim for the middle of my SWG range?
Yes. Targeting the mid-range often gives better stability and avoids high/low alarms.
Final takeaway
A pool salinity calculator saves time, avoids overcorrection, and helps your chlorine generator run efficiently. Use this tool with accurate testing and gradual dosing for the best water quality and equipment performance.