Chlorine vs. Saltwater Swimming Pools
More and more swimmers and homeowners are becoming uncomfortable with the health risks of swimming in chlorine. Although municipal regulations might require a certain amount of chlorine in pools, there are ways to get around them, if the alternative keeps the water as clean or cleaner.
Installing saltwater pools is one alternative, since chlorine comes from salt anyway. Here is a comparison between the two, with links to other alternatives at the end.
Swimming pools were first chlorinated in 1910 at Brown University by graduate student John Bunker (see link). By the 1950s, commercial compounds had been introduced into the market for use with public swimming pools. In 1961 the government became involved, with the US Department of Health issuing guidelines for construction and maintenance of swimming pools, including chlorination. In the mid-70s chemists began to discover the detriments of purifying with chlorine and the public began to look for alternatives. Chlorine pools are still prevalent, however, and in spite of health risks have many advantages.
Installation: Actual pool construction is the same for both chlorine and saltwater pools.
Pool maintenance: Water quality is controlled with chlorine tablets (sodium hypochlorite) or liquid chemical installed by hand. If whoever maintains the pool watches the timing, tests the water, and keeps good records, then chlorine input will be steady and adequate, however this is not usually the case.
Chlorine needs to be added several times per month, depending on usage, plus there is a certain treatment of additional chlorine called "shocking" that is recommended to kill any excess bacteria. Chlorine pools generally need cleaning every month or so.
Benefits: Installation costs are lower than the saltwater pool, in that a salt-to-chlorine conversion unit is not necessary.
Detriments: Chlorine has proven to cause breathing problems in professional swimmers. It also mixes with human sweat and saliva to form chloramines, which are harmful to human eyes, hair, and skin. These chloramines are typically removed from pool water with . . . more chlorine. And it destroys pool infrastructure.
Saltwater pools have been in production since the early 1980s, although they have only really become popular since 2000. Using a converter ionizer, saltwater pools convert salt into chlorine and calcium/salt residues. Titanium plates in the converter create a weak charge that catalyze the salt into forming chlorine. The salt residues adhere to the titanium. The level of salt used is approximately 3,000 parts per million (as compared with 35,000 ppm in ocean water), similar to what is in the human body.
Installation: You can convert your chlorine pool into a saltwater pool by purchasing and installing a saltwater converter and control box. The control box should be positioned out of direct sunlight away from garden sprinklers. The converter, which is a chlorine generator, should be placed as the last item that water flows through on its way to the pool (after heaters and other equipment). You can hire an electrician or pool installer to do the installation of high-end systems or purchase a DIY saltwater kit to install yourself.
Pool maintenance: Chlorine converters regulate the amount of chlorine made, releasing only when needed and keeping production steady. Beyond the periodic netting of leaves and other debris, saltwater pools need cleaning only once every few months, although it is important to check salt levels monthly. Calcium and other deposits left on the titanium plates need regular cleaning with a mild acid solution. Proper pH must be maintained with both systems.
Benefits: Softer water that feels better and is healthier to swim in. Saltwater removes chloramines on a steadier basis than does chlorine installed by hand. Easier to maintain. The latest technology can monitor and clean the water. No chlorine floater to contend with.
Detriments: Still produces chlorine and chloramines, although not as much. Attracts bees.
Since pool installation happens only once at the beginning, the main considerations in choosing a good pool should be:
Whether you can meet long term maintenance requirements and costs,
What and how often the pool will be used, e.g. is the extra cost worth it? and
The effect that swimming in such a pool will have on health (which could be costly).
Here is a chart that compares costs:
Cost to build
+ $700-900 for the converter
Avg. maintenance costs
$520 per summer (5 mos)
$150 + electricity 24hrs/day
High with skin/hair/eye irritations
Low with few chemicals used
Chlorine Free Swimming Pools
Chlorine is a health hazard. If you are not happy with either of the choices above, there are other types of pools available that are healthier, though also more costly. If you are choosing a pool for public use, then you must know and follow local laws. However the following links give you information on chlorine-free pools you can install in your own home.