Your pool salt sensor needs a good cleaning.

Clean the sensor first. That fixes it 90% of the time.

Salt cells and flow sensors get coated with calcium buildup. That crust throws off the reading, so the system thinks salt is low when it’s actually fine. Same thing happens if the sensor is dirty or the cell is scaling up.

Turn off the power. Pull the sensor (or the cell if it has a built-in sensor). Soak it in a dilute muriatic acid solution or a dedicated cell cleaner until the fizzing stops. Rinse well, reinstall, and recalibrate if your system allows it.

If that doesn’t do it, check water temperature — cold water can make some systems read low. Also make sure the flow is good (clean filter, no air locks). A wonky reading can also come from a failing sensor, but try cleaning first.

Don’t dump in a bag of salt until you’ve verified with a dropper test kit. That’s how you go from “low salt false alarm” to “now my pool is too salty.”