Updated October 10, 2026
A salt chlorine generator ("salt system") turns dissolved pool salt into chlorine automatically. But the #1 sizing mistake is buying a cell rated for exactly your pool volume. Here's why that's wrong — and what to buy instead.
The 1.5–2x rule
Buy a salt cell rated for 1.5 to 2 times your pool's volume. A cell rated exactly for your pool has to run at 100% output, all day, every day, to keep up. That burns through its lifespan fast. An oversized cell running at 40–60% output lasts years longer.
| Your pool volume | Minimum cell rating | Ideal cell rating |
|---|---|---|
| Up to 15,000 gal | 25,000 gal | 30,000–40,000 gal |
| 15,000–20,000 gal | 30,000 gal | 40,000 gal |
| 20,000–30,000 gal | 40,000 gal | 40,000–60,000 gal |
| 30,000–40,000 gal | 60,000 gal | 60,000+ gal |
Why oversizing pays for itself
A salt cell lasts roughly 10,000 operating hours. The math is simple:
- Right-sized cell at 100% output: ~10 hours/day → dead in under 3 years
- Oversized cell at 50% output: ~5 hours/day → lasts 5–7 years
Replacement cells cost $400–$800. Buying one size up (usually $100–$200 more upfront) can delay a $600 replacement by 2–4 years. It's the easiest money in pool equipment.
Salt systems worth buying
| System | Max rating | Street price | Notes |
|---|---|---|---|
| Hayward AquaRite S3 | 40,000 gal | ~$720 on sale | Industry standard, huge parts availability |
| Pentair IntelliChlor IC40 | 40,000 gal | ~$680 on sale | Great if you already run Pentair automation |
| CircuPool RJ-45 | 45,000 gal | ~$595 on sale | Strong value pick, long warranty |
What a salt pool actually is (and isn't)
Let's clear up the biggest misconception: a salt pool is still a chlorine pool. The generator converts dissolved salt into chlorine through electrolysis. The water feels softer and is gentler on eyes because chlorine levels stay low and stable — not because there's no chlorine.
You'll still need to balance pH, alkalinity, and CYA. You'll still shock occasionally. What you won't do is haul and dose chlorine every week.
Before converting: check that your heater's heat exchanger and any metal ladders/rails are rated for saltwater. Most modern equipment is, but older cupro-nickel exchangers and cheap stainless can corrode faster in salt pools.
Current salt system deals
Salt systems go on sale regularly — we've tracked 15–20% discounts across all three retailers. See today's pump & equipment deals →
Frequently asked questions
What size salt chlorine generator do I need?
Buy a salt system rated for 1.5 to 2 times your pool's volume. For a 20,000-gallon pool, choose a 40,000-gallon rated cell. Oversizing lets the cell run fewer hours per day, which dramatically extends its lifespan.
How long does a salt cell last?
A salt cell typically lasts 3–7 years, or about 10,000 hours of operation. Oversized cells that run at lower output percentages last toward the upper end of that range. Replacement cells cost $400–$800.
Is a saltwater pool really chlorine-free?
No — a salt pool IS a chlorine pool. The salt chlorine generator converts dissolved salt into chlorine through electrolysis. The water feels softer and is gentler on eyes and skin because chlorine levels stay lower and more stable than with manual dosing.
How much salt does a saltwater pool need?
Most salt systems need 3,000–3,500 ppm of salt, which works out to roughly 25–30 lbs of salt per 1,000 gallons for a fresh fill. A 20,000-gallon pool needs about 500–600 lbs (12–15 forty-pound bags) at startup.
Can I convert my chlorine pool to saltwater?
Yes — conversion is straightforward: install the salt cell in your plumbing after the filter and heater, add the control panel, dump in the salt, and balance the water. Most conversions take a few hours of plumbing work. Check that your heater and any metal fixtures are salt-compatible first.