Challenges with Salt Systems and High Calcium Hardness

Commercial Pool Water Chemistry
January 8, 2018
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February 5, 2018
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Bottomline, salt systems will not work in water with high Calcium Hardness (CH). Salt systems have been popular for quite some time now and when they are functioning properly it can make swimming in your pool a lot more enjoyable. For many, the water feels “softer”, it’s easier to manage chemistry (chlorine levels) and leaves you feeling much cleaner when you get out of the swimming pool! But, what happens when the calcium levels rise in the swimming pool causing the salt system to not operate correctly? This is a common problem, especially in the San Diego area and the Southwest United States where calcium and other hardness mineral levels are extremely high in our fill water! When residential and commercial properties purchase salt systems, this isn’t something that is usually brought to their attention and unfortunately when calcium scales the salt cell, it no longer works. Sure…. you can acid bath the cell but that takes life off of your cell, you could drain it and refill it with hard water again or you can recycle it using our Mobile Filtration Puripool Process!

The biggest challenge one will always have with salt systems is as water flows through the cell and along the electrode plates it begins to scale because the water is so hard. This can occur when hardness levels reach 400 parts per million (ppm) and higher! When the scale becomes thick the electrode plates will no longer manufacture chlorine. As the salt water flows through the cell, a low-voltage direct current is applied to flat, rectangular plates inside the cell, initiating electrolysis. Through electrolysis, salt and water break up into hydrogen gas and hypochlorous acid. The hydrogen gas simply leaves the swimming pool water in the form of small bubbles. The hypochlorous acid sanitizes the swimming pool water and ultimately reverts back into salt, and the process repeats. This process stops when calcium levels are too high, which means you will need to add chlorine to the pool or do something with the existing water! Trust us when we say, we show up to a lot of properties that mention they have a salt pool but they are using chlorine to sanitize the water!

Recently, we were called out to a 16,335-gallon swimming pool in Encinitas, California because their salt system wasn’t working. Typically, salt systems like to see calcium hardness between the levels of 200 and 400ppm, which is pretty hard to achieve in our area. When we showed up for the job the swimming pool yielded the following initial chemistry…

Total Dissolved Solids (TDS) – 6773ppm (irrelevant in a salt pool)

Calcium Hardness – 1830ppm (extremely high)

Salinity – 4475ppm (high)

Cyanuric Acid (CYA) – 65 ppm

After filtering the swimming pool for 14 hours we left our customer with the following end results, which is much better than a drain an refill, we conserved 85% of the existing water in the swimming pool and they now have a functioning salt system!

TDS – 917ppm

Calcium Hardness – 170ppm

Salinity – 703ppm

CYA – 0ppm

Our goal is to give you the best water possible. After filtration is complete please refer to the owner’s manual for the alt system to adjust chemistry as needed. If you’re interested in learning more about how our mobile filtration system can help you and your swimming pool, call us today at 1-800-535-0778

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