Here are ten easy steps to clean your cell suggested by Zodiac

1. Switch off the filter pump and chlorinator and close the necessary valves.
2. Unplug the cell terminal cap.
3. Unscrew the electrode retaining ring and remove the electrode.
4. Immerse the electrode in self-cleaning solution ensuring that the terminals are not immersed. The use of eye protection is recommended when working with pool chemicals. Zodiac also recommends you use an electrode cleaning solution from your pool professional as acid can be dangerous.
5. Allow the cleaning solution to dissolve the calcium deposits for about 10 minutes.
6. Rinse the electrode in clean water and refit the electrode into the cell housing.
7. Replace the cell head and plug assembly.
8. Reset the valves and switches.
9. Turn the pump and your chlorinator back on.
10. Confirm the chlorine output and check that the timer settings have been retained.