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How to Prevent and Remove Scale from Salt Cells

Scale buildup is one of the most common challenges for Salt Pool owners. This is because scale typically forms in hard to see places first, including the cell plates. The plates are inside the electrolytic chlorine generator (ECG), which uses electricity and dissolved salt (Sodium Chloride) to produce chlorine for the pool. The undetected buildup will eventually lower the effectiveness and shorten the lifespan of the cell. We here in Arizona are used to hard water, so scaling is all too common in our chlorine and salt pools!

What causes scale buildup in a Salt Cell?

The salt cell’s ECG can provide a perfect breeding ground for two reasons: heat and high pH production.

  1. HEAT - The hotter the water, the more calcium tends to drop out of pool chemical solutions and mineralize into a deposit. Since the cell plates generate heat, they tend to build scale after many uses. This is also why calcium often builds around pool heaters.
  2. High pH - pH is a by-product from the generator converting salt into chlorine (NaOH). If the pH level is not maintained, scaling may develop around the pool surface and equipment.

As scale builds on the cell plates, it begins to interfere with the chlorine production (electrolysis). This will not only reduce the unit’s efficiency, but it will begin to run hotter - increasing the scale buildup. Over time this can lead to permanent damage on the plates, including cell failure.

How to prevent scale buildup to the salt system

Leslie's Ultimate Scale and Stain Control

Leslie’s Ultimate Stain and Scale Control not only prevents calcium buildup, but also controls metal stains. Depending on the age of the buildup, calcium scale may take a few weeks for removal. Harder scales, especially in a salt cell, usually take longer and may require a second dose.

We recommend adding this product directly to circulating water to disperse the chemical. Pool owners should add this product to the pool water in increments of 5 oz. per month (for a 10,000 gallon pool).

Keep your water balanced. As stated earlier, balanced water is key. Leslie’s Dry Acid can help lower the pH level, balance Total Alkalinity and prevent calcium buildup around pool surfaces. We recommend testing your water at least once a week and adding Dry Acid as needed. For a more precise and comprehensive water analysis, bring a water sample to your local Leslie's store for a free AccuBlue® water test.

How to clean the salt cell and remove scale buildup

Here's what you will need:
1) Muriatic Acid (Sold in Leslie's Pool Supplies stores)
2) Plastic Bucket or Salt Cell Stand
3) Garden Hose

  • First, turn off the filtration system.
  • Then, carefully remove the salt cell from the union connections.
  • Now, rinse the cell plates with a garden hose.
  • We recommend wearing rubber gloves for the following steps.
  • If stubborn buildup is still present in the cell, then it’s time to use a mild acid wash. Mix a 4:1 solution of water and muriatic acid in a bucket (one quart of acid to one gallon of water). Always add acid to the water, not the other way around.
  • Connect the salt cell to a cell stand and pour the muriatic acid solution into the unit. Let the cell soak for 15-20 minutes. If you do not have a cell stand, carefully place the cell in a plastic bucket and add the acid wash solution until the plates are covered. Make sure not to cover the cell electrical connections. Again, let the unit soak for 15 minutes.
  • After the soak, rinse the cell again with a garden hose.
  • The acid mixture can be stored for later use or disposed of in a safe manner. Make sure to follow the chemical manufacturer’s recommendations when storing or disposing the water/muriatic acid solution.
  • Reinstall the cell.

Leslie's Ultimate Scale and Stain Remover

Here at Leslie’s we understand that some pool owners may not be comfortable using acid cleaners. A great alternative is Leslie’s Ultimate Scale and Stain Remover.

Leslie’s Ultimate Scale and Stain Remover, which is safe for all surfaces, is added to the water to slowly re-suspend the calcium carbonate. Calcium carbonate is easier to remove than the stubborn, gray-colored calcium silicate. Scale and Stain is applied by adding 16 ounces per 10,000 gallons of water to a bucket of pool water. The newly mixed water is then broadcast into the pool. Maintenance doses of this product may be applied every two weeks.

In-store Advice

If the salt cell is still not producing chlorine at an optimum level, we recommend that you bring it into your nearest Leslie's Pool Supplies store for a free, expert inspection. Depending on the condition of your salt cell, it may be time to purchase a replacement online at or in-stores.

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