SALTWATER POOL CHEMISTRY: SORTING FACT FROM FICTION
Understanding saltwater pool chemistry starts with sorting the facts from fiction. Many common misconceptions stem from a lack of knowledge around the chemistry of saltwater pools. The first misunderstanding is that they fundamentally different and don’t use chlorine as a sanitizer. Saltwater pools actually create free chlorine from the electrolysis of dissolved salt in the pool water. They experience many of the same problems as traditional chlorine pools, including problems with water balance, maintaining a chlorine residual, solving cloudy water and battling algae and breaking down combined chlorine.
Water balance is key to maintaining any pool. PH is a key water balance parameter. The process of generating chlorine causes the PH to rise over time. If left unchecked, PH will rise and can lead to multiple problems in the pool water, including ineffective sanitizing, cloudy water, scaling and algae. To combat this trend of rising PH, application of a weekly PH decreaser may be necessary for saltwater pools. Of course to determine this one must test the level of PH in the water, with test strips or a liquid test kit.
Another issue saltwater pools may experience is failure to maintain a free chlorine residual. This may be traced to a the pool experiencing a chlorine demand, or the cell may be no longer physically capable of producing enough free chlorine. The process of chlorine demand, and actually the lack thereof, quickly leads to problems such as cloudy water and algae. The problem may become too great for the chlorine salt cell to overcome. The addition of a full strength chlorine shock product is often needed to restore a sanitizer residual to the saltwater pool.
Don’t forget, over time the salt cell slowly wears out. This may cause it to produce less free chlorine than is needed. Also, not running the cell long enough will cause it to produce too little free chlorine. And an undersized salt cell will also be a cause for too little free chlorine being produced for the size of the pool.
Don’t forget to check the salt-level in the pool. Follow the manufacturer’s instructions for salt levels. Most recommend a range of 2600 to 3500 ppm of salt. Low water temperature will also cause the cell to stop making enough free chlorine. Most salt systems will shut down when temperatures reach below 60 degrees F. A traditional algicide should be used in saltwater pools just as in a typical chlorine pool.
With proper maintenance and a little care, saltwater pools provide a premium experience to pool owners.
From 2017 “THE EDGE” article by Alicia Stephens of Biolab,Inc.
Shortened for this blog by Rich of: www.paradisepoolandspa.com Cell Ph.609-313-0300