Replace the salt cell when it stops making chlorine.

You’ll know it’s dying when your chlorine levels stay low despite running the pump long hours and the cell is clean of scale.

Other signs: white calcium flakes floating in the pool (the cell is shedding buildup), error codes like “low salt” when your salt level is fine, or the cell just looks crusty no matter how often you clean it. If you have to run the pump 12+ hours a day to get marginal chlorine, it’s time.

Salt cells typically last 3-5 years depending on run time and water chemistry. A lot of people try to squeeze another season out of a tired cell and end up shocking the pool weekly. Not worth it. I’d replace it if it’s over four years old and acting up—you’re just burning electricity and frustration.

Don’t wait until algae takes over. A new cell is cheaper than a full green-to-clean recovery.