For many pool owners and prospective pools owners, there’s one big debate running through their minds right now: saltwater vs chlorine pools. In the past, pools usually had chlorinated water in them. However, today, there’s stiff competition between saltwater systems and the old chlorine treatment. If you’re curious about the differences between the two, here’s a brief primer.
The first time the idea of putting chlorine in pools came up, was back in 1894. A proposal was made to introduce highly toxic chlorine gas into water so that it would kill the germs found in it. This was first done for potable water. Chlorination itself became publicly available in the 1900s.
Around that time, bleaching powder, a mixture made by reacting chlorine gas with lime, was introduced. This was then used to first clean potable water supplies. Swimming pools themselves were a later beneficiary.
Take note though that swimming pools were a new thing in Europe and the United States at the turn of the century; the first modern swimming pools only came into being around the turn of the century, a product of better sanitation and waterworks. People were already well aware of the need for clean water for their pools, so they turned to filtering and normal cleaning; however, that was a time-consuming process.
This is where chlorination comes in. The first recorded entry for a chlorinated swimming pool was in 1910 at Brown University. The 70,000-gallon Colgate Hoyt Pool received chlorine treatment thanks to the efforts of a graduate student. It stayed sterile for four days thanks to the treatment.
Since then, chlorination spread like wildfire. By the mid-century, there was no swimming pool that did not get treated with chlorine. Nowadays, the chlorination process involves two-steps: a chlorine slow-release in the pool that keeps chlorine levels stable, while there is also the “shock” chlorine treatment that has pool technicians dumping chlorine into the pool to stabilize its sterility.
In 1974, studies showed that chlorine can react to some substances in contaminated water and result in toxic substances. This was when it was discontinued for drinking use. But, people still use it for swimming pools since pool water is not meant for drinking.
Chlorination is so popular for pools because it is very thorough in sterilizing water. It not only kills bacteria, it also disinfects the water and reacts to ammonia and other organic substances that make your pool dirty. For example, algae spores die quickly thanks to the presence of chlorine, ensuring that your pool won’t end up being home to the green menace.
Surprisingly enough, the biggest challenger to chlorination stems from chlorination itself. Saltwater chlorination was first developed in the 1970s, but exploded onto the world scene in the 1980s.
The idea behind it is pretty simple; since salt is sodium chloride, all you need to do is get the chlorine from the salt and combine it with other elements so that the chlorination comes naturally instead of a direct addition.
The process to free the chlorine is done via electrolysis. Saltwater from the pool is diverted to a chlorinator. Inside are two titanium plates coated with ruthenium. A low-level electrical charge is passed through them and a chemical reaction happens. Chlorine is produced and is naturally part of the water. The treated water is then recirculated back into the pool.
Interestingly enough, the pool needs to be sufficiently salty for the process to remain effective; this means introducing salt into the system at the bottom of the pool. This is then spread by a pool brush so that the pool is equally saturated in salt. You will also have to add hydrochloric acid on a regular basis to return the pool to a neutral state since the salt raises its alkaline levels.
There are several advantages and disadvantages on both sides of the equation. Chlorine is the traditional choice and a lot of people are familiar with it. It’s also pretty easy to deploy; just buy some chlorine tablets and dump them into the pool on a regular basis. It works and has been effective for more than a century.
The main trouble with chlorine is that it can be a struggle to maintain levels properly. Chlorine tablets can last for days, but they can vary. You might mistakenly dump too many into the pool and over-chlorinate it; you can also under-chlorinate.
In addition, chlorine can be pretty harsh. If you’ve ever jumped into the pool and felt the sting in your eyes, then you understand what this means. Constant exposure can also be bad for your skin. Ever noticed how dry your skin was after a dip in the pool? This is why it is recommended to shower after you go swimming.
Saltwater pools have their own advantages; the main one being that it is a lot milder. Though it may sound like the pool is like the ocean in salinity, it’s actually 1/10 of the usual saltiness. The result is that you can have the experience of swimming in clean and fresh water; it is a lot safer on your eyes and skin. Besides that, maintenance is just a matter of cleaning the chlorinator. This is usually done every few months as the minerals build up on its titanium plates.
It’s not perfect though. You’re going to have to spend a lot upfront to add a chlorinator system to your pool. Besides that, it can be complicated and difficult to fix if something goes wrong. The presence of salt is also a big problem. Saltwater is very corrosive and you can expect your pipes and the various surroundings of the pool to take a beating.
Still, as the pool owner, you’ll be the one making a choice between the two. Weigh the pros and cons and make an informed choice that you’ll be happy with.