How to clean a pool salt cell

Inspect it every three months, and clean it only when you see scale. Hayward's AquaRite manual recommends opening and inspecting the cell every three months or after cleaning the filter, and its control flashes an Inspect Cell light after about 500 hours of running. Hot summers and hard water mean more scale, so look more often from June to September.

Look through the end of the cell at the plates. White, crusty or flaky deposits between the plates are calcium scale. Leaves or grit caught on the plates mean something is getting past the filter.

Rinse it first. Turn off the power to the system, take the cell out and spray the plates with a strong garden hose stream. Hayward's manual says deposits that will not rinse off can be scraped with a plastic or wooden tool, never metal, because metal scratches the coating off the plates.

Only for heavy scale that rinsing will not move. Hayward's method: in a clean plastic container, mix four parts water to one part muriatic acid, adding the acid to the water and never the water to the acid. Wear rubber gloves and eye protection. Stand the cell in the solution so it covers the plates but not the wiring, let it soak a few minutes, then rinse it with the hose. Repeat if scale is still there.

Some owners do for light scale. It is much weaker than muriatic acid, so it takes far longer and does little on heavy buildup. Whatever you use, read your own cell's manual first, because some makers specify their own cleaning method and solution.

High pH and high calcium. A salt cell pushes the pH up as it works, and calcium comes out of the water as scale where the water is warmest, right at the plates. Hayward notes that buildup on the cell points to an unusually high calcium level. Keep the pH around 7.2 to 7.6 and calcium and alkalinity in range, and the cell needs cleaning far less often. See how to raise or lower pool alkalinity. If you would rather not chase the balance yourself, our weekly pool service tests the water every visit and corrects it, with the chemicals included.

Several years, depending on how many hours it runs, how it is sized for the pool and how well the water is kept. Cleaning with acid more often than needed shortens its life, so rinse first and save acid for scale that will not come off any other way. If the cell still reports low output with the salt level right and the plates clean, Hayward's manual says it may be worn out and need replacing.

Whatever your cell's manual says. Hayward's AquaRite manual lists 2,700 to 3,400 ppm of salt, with stabilizer at 60 to 80 ppm. Salt and stabilizer fall together as water is replaced, so test both at the same time. More on salt pools in salt water vs chlorine.