Domakihub How to Clean a Pool Salt Cell (and Keep It Working)
Remove calcium scale properly so your salt chlorinator produces chlorine efficiently all season.
Reviewed by Domakihub pool pros · 2026-06-23 · 5 min read
A salt chlorinator cell is the heart of any saltwater pool — it converts dissolved salt into free chlorine through electrolysis. Over time, calcium carbonate builds up on the metal plates inside the cell, cutting chlorine output and shortening the unit's life. The video above walks through the full procedure visually; the steps below give you a clear sequence to follow at your own pace, whether you manage a private home, a holiday villa, or a hotel pool in Greece.
Why Calcium Scale Is the Enemy of Your Salt Cell
Saltwater pools in Greece face a double challenge: high ambient temperatures accelerate scale formation, and many local water supplies have elevated calcium hardness. When calcium carbonate coats the titanium plates inside the cell, the electrical current has to work harder, efficiency drops, and your controller starts showing low-chlorine warnings even though salt levels are fine.
Manufacturers typically recommend inspecting the cell every three months and cleaning it when you see visible white or grey deposits. A cell that is kept clean can last eight to ten years; one that runs scaled rarely makes it past three or four.
What You Will Need Before You Start
You need muriatic acid (hydrochloric acid at around 31%), a plastic bucket, water, a garden hose, rubber gloves, eye protection, and a cell-cleaning stand or end caps to seal one end of the cell during soaking. A mild alternative for light deposits is distilled white vinegar, though it works more slowly and is best for preventive maintenance rather than heavy build-up.
Never use a metal brush or screwdriver to scrape the plates — this damages the ruthenium-iridium coating that makes electrolysis possible. Chemical cleaning is the only safe method.
How to Clean Your Pool Salt Cell: 5 Steps
- 1
Switch off the system and remove the cell
Turn off the salt chlorinator at the controller and isolate the pump. Undo the unions on both ends of the cell — they are hand-tight on most Hayward, Pentair, and Astral models. Carry the cell to a shaded work area; direct sunlight heats the acid mixture unevenly and increases fume risk.
- 2
Inspect the plates with a torch
Shine a flashlight through one end of the cell and look at the parallel titanium plates. Light, chalky deposits can be removed with a 4:1 water-to-acid ratio. Thick, hard scale that has turned grey or brown needs a 10:1 ratio for an initial soak. Note any cracked or corroded plates — those signal it is time to replace the cell rather than clean it.
- 3
Mix the cleaning solution and soak the cell
Always add acid to water, never water to acid. For a standard clean, mix one part muriatic acid into four parts water in a plastic bucket. Seal the bottom of the cell with the end cap or cleaning stand, stand the cell upright, and pour the solution in until the plates are submerged. Let it soak for 15 minutes. You will see the solution fizz as it dissolves calcium — this is normal. Do not exceed 15 minutes or you risk etching the coating.
- 4
Rinse thoroughly and inspect again
Pour the spent acid solution into a waste container (neutralise with baking soda before disposal). Flush the inside of the cell with a strong stream of water from a garden hose for at least two minutes. Look through the cell again — the plates should appear clean and metallic. If patches of scale remain, repeat the soak for a second 15-minute cycle using fresh solution rather than extending a single soak.
- 5
Reinstall, check salt level, and run a short test cycle
Reattach the cell to its unions, making sure the O-rings are seated and lightly lubricated with silicone grease. Restart the pump and chlorinator and observe the controller readout. If the cell was heavily scaled, chlorine output may have been suppressed for days; check the pool's free-chlorine level an hour after the clean and dose accordingly. Log the date so you know when the next inspection is due.
Rather have a pro handle it?
Get a vetted pool pro in your city — one number, booked in EN/EL/DE.
FAQ
- How often should I clean a salt cell in a Greek summer climate?
- In Greece, high water temperatures and typically harder tap water mean calcium builds up faster than in cooler climates. Plan to inspect the cell every two to three months during the swimming season (April to October) and clean it whenever you see visible scale. A visual check takes less than two minutes and can save you an expensive service call.
- Can I use vinegar instead of muriatic acid?
- Yes, for light or preventive cleaning. Fill the cell with undiluted 5% white vinegar and let it soak for several hours or overnight. Vinegar is safer to handle and does not produce fumes, but it cannot dissolve heavy calcium deposits. If the scale is thick or has hardened, muriatic acid is necessary.
- My controller shows a low-salt warning but I tested the water and salt is correct — what is happening?
- A scaled salt cell is the most common cause of this false low-salt reading. The calcium coating interferes with the conductivity measurement the controller uses to estimate salt concentration. Clean the cell first, then re-test. If the warning persists after a thorough clean, the cell may have reached the end of its service life and need replacement.