Saltwater Pool Systems vs. Freshwater Pools
The fundamental difference between a saltwater pool (otherwise known as a salt chlorine pool) and a freshwater pool is the way each pool system obtains chlorine to eliminate bacteria.
A saltwater pool system uses a chlorine generator to break down salt and release chlorine gas into the pool water. On the other hand, in a freshwater system, chemical tablets containing chlorine must be regularly added to the freshwater pool to kill bacteria and keep the water clean.
Why are Saltwater Pools Preferred Over a Freshwater Pools?
Here are a few reasons to choose a saltwater swimming pool over a freshwater swimming pool:
Chlorine works together with the pool filtering system to kill bacteria and keep your pool clean. A freshwater pool will require adding chemical tablets periodically. This can be time-consuming and difficult to manage based on your schedule. A salt chlorine pool has a special chlorine generator. It passes tiny electrical charges through the water to separate oxygen and hydrogen. Salt (brine block or non-iodized table salt) is added, and reacts with hydrogen in the water to form chlorine, which kills the bacteria present in your pool. The process is carried out automatically in a saltwater pool, and that means you don’t have to keep purchasing and/or adding chlorine. This reduces frustrating maintenance and saves money, since the task of adding chlorine into your pool is never a concern.
A Wise Investment
The initial cost of installing and maintaining a pool is probably the key factor for most people who build a new pool. And the fact is, saltwater systems are more expensive up front. But for homeowners who are able to make a slightly higher upfront investment, constantly adding chlorine to a freshwater pool makes it more costly to maintain in the long run because the chlorine expenses will surpass the initial investment cost of a saltwater pool. From a long-term perspective, it is wiser to invest in a saltwater pool than a freshwater pool due to lower ownership and maintenance costs in the long run.
The raw chlorine that should be added regularly to a freshwater pool creates an unpleasant chemical smell. That smell is typically absent in a saltwater pool. This chemical odor can have bad health effects to pool users, especially those with breathing conditions such as asthma. Since the chlorine is generated from within a saltwater pool and in small doses, someone swimming cannot smell it. So, if you or a family member has a respiratory disorder, a saltwater pool would be a better option than a freshwater pool.
Cost of Operation
A saltwater chlorine generator can cost over $1,000. Add to that the cost of installing the system, and most saltwater pools will cost about $1,400 to $2,600 more than a traditional freshwater pool. The equipment will also be required to run for more than 20 hours in order to produce enough chlorine, leading to slightly higher monthly energy bills.
However, the cost of stabilizer chemicals and chlorine tablets for a freshwater pool is about four times more than the relatively low cost of non-iodized salt for a saltwater pool. Plus, you should take into consideration your own time and labor in measuring chemicals and adding chlorine tablets. This is why in the long run, a saltwater pool is cheaper to operate than its freshwater counterpart.
Brief History of Saltwater Pools and Their Popularity Today
Saltwater pool technology began in Australia in the 1960s. It was later applied in California in the 1980s. Saltwater pool systems have gained popularity quickly across the U.S. According to an overview report published in Pool and Spa News, about 1.4 million saltwater pools have been constructed and are already in operation in the U.S. The report also mentions about 75% of all new in-ground swimming pools are saltwater models compared to only 15% in the last 15 years. Today, California is among the leading places for saltwater pools, with many residents adopting the technology for its eco-friendliness and efficiency.
How Do Saltwater Pools Work?
- Saltwater pool systems draw on salt dissolved in the pool water to produce chlorine. The chlorine generator, also known as a salt cell, breaks down salt (sodium chloride) in water through a process called electrolysis.
- The electrolysis creates hypochlorous acid and hypochlorite, which are oxidizing or sanitizing agents similar to chlorine used in freshwater pools. These chlorine-like chemicals are responsible for cleaning the pool water without adding chlorine chemicals in tablet form.
- A by-product called chloramines are generated in small amounts. However, the electrolysis oxidizes the chloramines that normally causes chemical odor and eye irritation in freshwater pools.
Can You Taste Salt in a Saltwater Pool?
The taste of saltwater pools is similar to freshwater pools because the amount of salt present is quite small. The concentration is typically lower than the minimum detectable quantity by taste, and there is no noticeable salty residue on your skin or hair after bathing. We liken the salt concentration in saltwater swimming pools to a milder solution used for contact lenses. This means bathers can swim comfortably and leave the pool with skin feeling natural and smooth.
Basic Saltwater Pool Maintenance
The chlorine generator and the technology used in pool testing make saltwater pool maintenance stress-free. Less time and money is required to monitor the pool. The water is naturally stable, therefore you can save time and money on balancing chemicals.
Most saltwater pools should operate at 2,500 to 4,500 ppm salt concentration on a weekly basis according to a manufacturer’s specifications. Your pool will only run efficiently at the desired range, which varies with different models. Operating your pool with low sodium levels can reduce the chlorine generation in your swimming pool and lead to unsanitary conditions. Some new models come with built in salt level monitors or automatic salt feeders. If your pool does not have these features, you can call us to test salinity concentrations on a weekly basis. We highly recommend operating at the salt level specified for your generator so it runs effectively and lasts longer.
Free available chlorine (FC) levels
The recommended weekly level for free available chlorine is 1 to 3 ppm, but the optimal level is 2 ppm. It should be monitored every 2 to 4 weeks or more frequently if you are seeing irregularities in this or other chemical levels. If low FC levels are discovered, the first thing to check is your level of salinity, since your chlorine generator relies on a steady supply of sodium to create chlorine agents. Aside from that, low FC levels are commonly caused by an expired chlorine generator, calcium buildup, or insufficient pool circulation.
While saltwater pools generally don’t have problems with acidity, you may find that your pH does creep up over time. Adding acid to your pool may be required to keep the pH levels around 7.5.
Cleaning the chlorine generator
Most chlorine generators should be cleaned once a year to prevent calcium buildup that can lead to reduced chlorine production. With standard use and proper chemistry maintenance, a chlorine generator can last for 4 to 6 years. You can call us to handle both the annual cleaning and the inspections (which should be done every 2 to 3 months). If you notice debris or calcium deposits, those are good indicators your chlorine generator needs to be cleaned to boost its efficiency
There are other maintenance services that should be done on your pool on a weekly, monthly, and yearly basis. We can assist you by inspecting your pool and suggesting the best maintenance approaches to ensure your swimming pool continues to run effectively.
What are the Drawbacks of Saltwater Pools?
Despite saltwater pools being generally superior to freshwater pools, there are various drawbacks associated with them:
- The possibility of corrosion on metallic ladders and internal pump parts from the mild salinity in the water
- Over time, salt can leave corrosion on stones or pavements, which may become hard to clean off
- Salt has been found to damage underwater lights or other submerged electrical circuitry
- The chlorine generator may increase your monthly energy bills, especially if you have a large swimming pool that is frequently used