From time to time a question about salt water pools comes up. As you can tell from the title, I am not a fan and I will not put a fountain, sculpture, or spillway into one. Here is why:
Salt systems make chlorine to treat water by ionizing salt, sodium chloride, so that the sodium and chloride ions separate and the chloride is then available to cleanse the water. That is, the end result is exactly the same as adding chlorine the traditional way. For this process to work, a small amount of salt is dissolved in the pool water. Good for your skin, but terrible for everything else.
We all know that salt is corrosive. In the snow-belt, salt on roads eats cars and destroys road surfaces. If you live near the ocean, you will have seen the salt air corrode pipes, eat heating ducts, damage cars, and generally attack anything that stands still.
It turns out that even the small amount of salt dissolved in swimming pool water also attacks the environment around it. I have seen natural stone deeply etched in a matter of months just by having the pool water run over it. After talking with professionals in the stone business and with pool builders and doing some research, I discovered that the small amount of salt in the water attacks natural stone, concrete, steel, stainless steel, pool cover mechanisms, grout, pool and pond liners, and even the decking where there is splash out.
So the main reason I don’t like salt systems is that they attack sculptural materials destroying the works of art. But there are a number of other issues.
The salt generators also attract calcium from pool plaster to their titanium plates which they then put back into the pool water causing a calcium buildup on the pool surface and scaling where it is deposited on the pool walls and any other surface. You can also get a residue of salt around the edge of the pool and in areas where swimmers drop water, such as in front of pool ladders.
The backwash from salt pools can kill plants and enough of it can poison the ground. It is thought to be a bad enough environmental problem that salt systems have been banned in a number of municipalities across the US. For all these reasons, salt systems are not a great choice.
What are better alternatives? There is always the traditional chlorine additive. But, two new solutions have come on the market in past several years that seem to better for people, the water and the environment - Ultraviolet light systems and Ozone generators. Both types of systems are being used across the country in residential, commercial and public pools.