Expert Verified Updated: March 2026

Salt Cell Generator Run Time Calculator

Calculate how many hours you must run your Salt Water Chlorine Generator (SWG) to achieve your daily free chlorine requirement.

Quick Conclusion
If a salt cell produces 1.4 lbs of chlorine per 24 hours running at 100%, and your 15,000-gallon pool needs 2 ppm added daily, you must run the pump and cell for exactly 5.15 hours.

Technical Comparison

Cell Size RatingTypical Yield (lbs/day)Optimal Pool Size
15,000 Gal0.6 lbsUnder 10,000 Gal
25,000 Gal1.0 lbs15,000 Gal
40,000 Gal1.45 - 1.5 lbs25,000 - 30,000 Gal
60,000 Gal2.0+ lbsAbove 30,000 Gal
Most pool owners guess their SWG settings and either burn out their expensive salt cell in 2 years (by running it 24/7 at 100%) or get recurring algae blooms from under-chlorination.

Actionable Steps

1. Test how much chlorine your pool loses on a normal sunny day (usually 1.5 to 2.5 ppm). 2. Input your pool volume and cell output rating. 3. Look at the required hours. 4. Match your pump timer exactly to that duration, with the SWG cell set to 100%.

Pro-Tip

Always oversize your salt cell! If you have a 20,000 gallon pool, buy a 40,000 gallon cell. You can run it at 50% output, which preserves its lifespan and runs cooler, saving you hundreds of dollars in replacement costs.

Frequently Asked Questions

How do I find my cell's output rating?

Check the manufacturer's manual. A cell rated for a '40,000 Gallon Pool' (like the Hayward T-Cell-15) typically produces 1.4 to 1.45 lbs of chlorine gas per 24 hours.

What if my unit is set to 50%?

If you set the percentage dial to 50%, simply double the required hours calculated above. (e.g., 5 hours at 100% is the same output as 10 hours at 50%).

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