It is vital that owners of saltwater pools know how to clean a saltwater chlorinator cell to remove calcium scale and maintain the operation of the chlorinator. Calcium scale accumulation is one of the most common problems with swimming pool filtration systems and saltwater chlorinator devices.
The saltwater chlorinator cell passes a very low voltage, high electric current through the saline pool water to produce free chlorine. This free chlorine sanitizes your pool water by destroying algae, bacteria, viruses and other contaminants.
Saltwater chlorinators are low maintenance devices but eventually your chlorinator electrolytic cell will accumulate calcium scale and require cleaning. The calcium scale interferes with the electrical efficiency of the electrodes in the cell reducing the cell’s chlorine production.
Cleaning the chlorinator cell is a simple procedure that all pool owners can learn. If you live in an area with high water hardness you will have to clean your saltwater chlorinator cell more frequently than normal.
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Saltwater Chlorinator Cell Installation
It is vitally important that you install your saltwater chlorinator unit according to the manufacturer’s specifications. This will ensure correct operation of the unit.
Install the electrolytic cell within 1.5 meters of a wall with an electrical power supply for the control unit. Otherwise, you need an electrical contractor to install an additional power point on a post for the control unit. The electrical contractor may hardwire a longer power cable from the control unit to the chlorinator cell. And install the control unit at least one meter above the ground level.
Install the saltwater chlorinator unit horizontally. It must be within 5 degrees of level to ensure correct operation of the electrolytic cell.
In most electrolytic cells the water can flow in either direction so it doesn’t matter which way round you install the chlorinator unit.
Install the chlorinator electrolytic cell last after all the other pool filtration equipment. That is, all other pool filtration equipment (filter, heater, valves) comes before the saltwater chlorinator unit. The saltwater chlorinator water outlet flow must be directed into the swimming pool or spa pool.
How Does My Saltwater Chlorinator Work
A saltwater chlorinator unit is a clear electrolytic cell where a very low voltage, high electric current is passed through the saline water to produce chlorine. Pool salt is the chemical compound sodium chloride (NaCl). The electrolytic cell splits the pool salt into sodium and chlorine ions (Na+ and Cl-). The free chlorine immediately binds and destroys algae, bacteria, viruses and other contaminants. Then the chlorine reverts back to dissolved salt completing the cycle. The destroyed contaminants are trapped in the filter making your pool water safe, clean and clear.
All saltwater pools contain chlorine as it is produced by the chlorinator unit to sanitize the pool. However, the chlorine level in saltwater pools is lower than a freshwater pool. The chlorinator unit is constantly generating chlorine throughout the day and night whenever the pump is running. So salt pool water will be gentler on your skin, eyes and swimwear.
How Salty is a Saltwater Pool?
Pool salt is purified crystallized common salt made from sodium chloride.
The concentration of salt is 3000 to 7000 mg/l (ppm) for a saltwater pool which is only about 10 to 15% of the salt found in seawater (35,000 ppm).
The concentration of salt in a pool is about equal to the salinity of the tears in your eyes. So opening your eyes underwater will be perfectly comfortable.
Saltwater Chlorinator Controls
All saltwater chlorinators have a control panel to regulate the level of chlorine production and run time of the pump motor.
Turn up or down the chlorine control switch to alter the amount of chlorine generated by the electrolytic cell. In the summer season or when the pool is in heavy use turn up the dial for more chlorine. During the winter dial down the chlorine production as required.
Alter the pump timer settings to run the pump longer or shorter hours as required.
In the summer season run the pump longer to generate more chlorine and filter the water for a longer period.
During the winter run the pump motor less hours daily.
I recommend to run the pump 8 hours daily in the summer and 4 to 6 hours daily in the winter.
Read our article on How Many Hours to Run the Pool Pump
How Frequently to Clean a Saltwater Chlorinator Cell
Saltwater chlorinators are low maintenance devices. They are designed to operate for extended periods of time with minimal maintenance or cleaning. However, eventually your chlorinator electrolytic cell will require cleaning. Most saltwater chlorinator cells require cleaning every 12 months.
Please read the manufacturer’s instructions for your model of saltwater chlorinator to determine how frequently the cell requires cleaning.
How to Remove Calcium Scale from a Saltwater Cell
Calcium scale (or lime scale) accumulates on the chlorinator electrolytic cell reducing the effectiveness of the cell’s operation. The accumulation of scale is more common in locations with hard water due to higher calcium levels in the water supply.
Other factors that cause calcium scale are warm pool water and higher than normal pH.
If you are finding you need to dial up the chlorine production on the chlorinator control panel it’s time to clean the chlorinator cell.
Prepare the Cell
- Switch off the filtration system at the power source.
- Remove the power plug from the power supply.
- Remove the chlorinator unit from the plumbing line by carefully unscrewing the pipe connectors at the inlet and outlet ports of the chlorinator unit.
- Rotate the chlorinator unit so the inlet and outlet ports face upwards.
- Place the unit on a level concrete (or non-metallic) surface.
Warning: Please wear rubber gloves and eye protection before handling chemicals
Prepare the Cleaning Solution
- Prepare an 8:1 acid cleaning solution in a plastic bucket. Add 2 liters of water to the bucket first. Then carefully add 250ml of hydrochloric acid into the water. Mix the water with a plastic or wooden stirrer.
- Carefully pour the acid cleaning solution into the upturned chlorinator unit. Fully cover the electrodes with the cleaning solution.
- Allow the unit to stand for 15 to 20 minutes. Afterwards empty the cleaning solution into a drain. Flush the chlorinator unit with fresh water several times to remove all traces of the acid solution. If the cell is very dirty repeat the cleaning process with fresh cleaning solution.
- Refit the chlorinator unit to the plumbing line by carefully screwing up the pipe connectors at the inlet and outlet ports of the chlorinator unit.
- Reconnect the power plug and switch on the unit.
- Run the pool pump manually to check for any leaks in the plumbing around the chlorinator unit.
- Ensure the chlorinator control unit indicates that chlorine is being generated by the cell.
- Switch your pool system to automatic control.
How Long Should Your Chlorinator Cell Last?
A correctly installed and maintained saltwater chlorinator cell has a normal life expectancy of at least 3 to 5 years.
The life expectancy will vary considerably depending on the use of the swimming pool.
A saltwater chlorinator cell that operates for only 4 hours daily is expected to last twice as long as a cell operating 8 hours per day.
Pools in a tropical climate are in use all year round and will have a reduced cell life expectancy.
Swimming pools in a cooler climate that are only in use during the summer season may achieve a higher cell life span than normal.
Common Causes of Chlorinator Cell Failure
- A low water flow rate through the electrolytic cell shortens the cell lifespan. A low water flow is caused by poor filter maintenance, a worn out filter cartridge, partially blocked plumbing, calcium build-up in pipes or a faulty pump motor.
- Physical damage to the cell electrode coating. Poor handling and maintenance of the electrolytic cell cause damage. For example, the cell may have been cleaned incorrectly.
- Insufficient salinity level in the pool water. The minimum salt level is 3000ppm. When the pool water does not contain enough salt the cell cannot operate correctly and may damage the cell.
- Too much salt in the pool water. This may cause the chlorinator unit to not operate effectively leaving the water unsanitized. If there is too much salt in the pool water you need to dilute the water by draining some of the water and refill the pool.
- Excess accumulation of calcium deposits on the cell electrodes. The electrolytic cell will not function correctly with calcium deposits on the electrodes.
- Cleaning the electrolytic cell in an acid solution that is too strong. The cell can be damaged by using an acid solution that is stronger than 1 part acid in 8 parts water.
- Cleaning the cell for too long. Do not expose the electrolytic cell to the acid cleaning solution for more than 20 minutes.
Read our article on Best Salt Water Pool Chlorinator
Conclusion
Clean your saltwater chlorinator cell annually in a mild acid cleaning solution.
This simple maintenance procedure improves the chlorinator’s operating efficiency and prolongs the cell’s lifespan.
However, when the chlorinator fails to produce sufficient chlorine replace the cell with a new unit.
