Swimming pool salt systems use disolved salt at a concentration of 1,800 to 6,000 parts per million (ppm) as a store for the pool’s chlorination system. The pool’s chlorinator breaks down the salt by the process of electrolysis. The chemical reaction produces hypochlorous acid and sodium hypochlorite. These two chemicals are the sanitizing agents that are already commonly used in swimming pools.
There may be some misperception that swimming pool salt systems are chlorine-free, but that is not the case. Instead, it uses a chlorine generator rather than direct addition of chlorine into the pool. The difference between swimming pool salt systems and regular chlorine pools is that saltwater pools do not have something called chloramines. Chloramines are the irritating chemicals that can cause pools to sting the eyes and have a chlorine smell. The process of electrolysis gets rid of chloramines in the same way that shock oxidizer does.
When the levels of chlorine in the pool are low, one cause may be low salt levels, which can be caused by water splashing out, backwash, and dilution of pool water by rain water. There have been reports that swimming pool salt systems can still generate unhealthy trihalomethanes (THMs), which are disinfection byproducts. One of these THMs is bromoform, and very high levels of it have been reported in some public saltwater pools. However, it is believed that these conditions are only found in pools that are heavily trafficked and / or poorly maintained.
While swimming pool salt systems are relatively new in the United States, they have been common in Australia for a long time. When they are maintained properly, swimming pool salt systems are considered the best way for homeowners, water parks, and hotels to care for pools. Benefits include convenience and constant chlorine-based sanitizer delivery. The initial costs are higher, however, and salt can damage some metals and some types of stone that have not been properly sealed.
