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2014SumShotcreteEMag

Pool & Recreational Shotcrete Corner Saltwater Pools By Mason Guarino Byears have heard about the “new” tech- America in the mid-1980s. So this “new” tech- -The saltwater technology was originally invented in the 1960s in Australia and brought toy now, most people who have a pool orhave been around pools in the last few nology of using salt water in pools. Comments nology is not so new. In fact, it is has already been often include how great they are and how good around long enough to make it illegal to connect the water feels. Saltwater pools do typically have a saltwater pool system to the city sewer system a soft water feel to them, but chlorine is still in certain parts of the country. Santa Clarita Valley, needed in a saltwater pool. There are a few mis- CA, has put this ban into effect to meet their state- conceptions, however, surrounding saltwater mandated chloride limits in wastewater discharge. pools that need to be considered. Other municipalities have banned the technology all together. When saltwater pools are drained, the salt is discharged into parts of the ecosystem that are damaged by the high-chloride salt, including plants, animals, and drinking water supplies. Saltwater pools use what is called a saltwater chlorine generator. This device, in the plumbing system end of the equipment, takes the dissolved salt in the pool water and separates the sodium ions from the chloride ions using positive and negative electrical charges. The chloride ions then turn into chlorine gas that reacts with the water creating hypochlorous acid, or what is typically referred to as chlorine, in the swimming pool. However, in addition to the chlorine being created in the pool water, sodium hydroxide is also created when the sodium ions are separated from the chloride ions. Sodium hydroxide is very alkaline and will raise the pH of a swimming pool. When the pH is raised by the sodium hydroxide, the hypochlorous acid ions will separate. This separa- tion significantly reduces the bacteria- and germ- fighting chlorine because the hydrogen ion wanders off and the hypochlorite ion starts to be corrosive to its environment, namely the pool itself. This is combatted by adding muriatic acid on a regular basis instead of chlorine. This keeps the pH level normal and keeps the hypochlorous acid (chlorine) intact and able to fight off the bacteria and germs in the pool. As with every pool, maintenance and upkeep are essential to allowing the pool a long service life. As we all know, sometimes maintenance can be neglected. The effects of neglecting the main- tenance on a typical chlorine pool will become obvious quickly—the pool will turn green and things will start to grow in a short period of time. Fig. 1: Pools with salt still look the same as pools without Neglecting the maintenance on a saltwater pool 28 Shotcrete • Summer 2014


2014SumShotcreteEMag
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