Staff Answer
May 07, 2026 - 11:09 AM
These flakes will almost certainly be calcium carbonate, just like the predominant buildup that occurs on your salt cell. Contributory factors include high readings for Calcium Hardness, pH, Total Alkalinity, water temperatures, output settings on the chlorinator, and the Saturation Index.
Your pH and Total Alkalinity can be lowered with Muriatic Acid. Calcium Hardness can really only be brought down by draining some water and topping up with water that has a lower Calcium Hardness—this can be a problem in some parts of the country. For most pool owners, there’s little to be done about water temperature, but the SCG can be set at a lower output level and run for a longer period of time, which will help with the flakes and also contributes to extending cell life. Indirect help can be obtained from assuring that your Stabilizer/Cyanuric Acid (CYA) level is between 30 and 50 ppm, since some chlorine is lost to the sunlight below 30 and the chlorine’s efficacy is reduced above 50 ppm. The point in optimizing your CYA is to lower demand from your SCG. Similarly, check that your Combined Chlorine is below 0.5 ppm so that your Free Chlorine isn’t trying to oxidize the Combined Chlorine and unnecessarily requiring the SCG to be operated at a higher output setting. Aside from changing the output setting and runtime for the SCG, these other changes all serve to lower the Saturation Index. So, an LSI calculator is the perfect tool for bringing the water back into balance. By adjusting the inputs and seeing the calculated change in the index, you can determine what changes will bring the water back into balance and reduce or eliminate the white flakes.
Your pH and Total Alkalinity can be lowered with Muriatic Acid. Calcium Hardness can really only be brought down by draining some water and topping up with water that has a lower Calcium Hardness—this can be a problem in some parts of the country. For most pool owners, there’s little to be done about water temperature, but the SCG can be set at a lower output level and run for a longer period of time, which will help with the flakes and also contributes to extending cell life. Indirect help can be obtained from assuring that your Stabilizer/Cyanuric Acid (CYA) level is between 30 and 50 ppm, since some chlorine is lost to the sunlight below 30 and the chlorine’s efficacy is reduced above 50 ppm. The point in optimizing your CYA is to lower demand from your SCG. Similarly, check that your Combined Chlorine is below 0.5 ppm so that your Free Chlorine isn’t trying to oxidize the Combined Chlorine and unnecessarily requiring the SCG to be operated at a higher output setting. Aside from changing the output setting and runtime for the SCG, these other changes all serve to lower the Saturation Index. So, an LSI calculator is the perfect tool for bringing the water back into balance. By adjusting the inputs and seeing the calculated change in the index, you can determine what changes will bring the water back into balance and reduce or eliminate the white flakes.
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