Salt Water Swimming Pool Basics

Written by Michael Dean
September 21, 2023

saltwater swimming pool

A saltwater pool could be a great alternative to traditional chlorine pools. There are quite a few differences in the mechanics of the two. This article will discuss the pros and cons, annual costs, design considerations, maintenance of a saltwater pool, and more. Let’s get to it!


Main Takeaways

  • A saltwater pool uses a salt chlorine generator to convert salt into chlorine to sanitize the water, using a process called electrolysis.
  • Some advantages of a saltwater pool include lower annual costs, softer and gentler water, and better for the environment.
  • Some disadvantages of a saltwater pool include a higher initial cost and corrosion.
  • Make sure to use salt that is at least 90-95% sodium chloride and aim to add between 2700-3400 ppm.

What is a Salt Water Pool?

A saltwater pool is a pool that is chlorinated using a special piece of equipment called a salt chlorine generator. You can use regular salt in a salt water pool as long as the salt doesn’t contain too many impurities. Ordinary salt is chemically made up of two elements: sodium and chlorine. When pool water comes into contact with the salt chlorine generator, the machine turns the salt in the water into hypochlorous acid.

Hypochlorous acid is also produced when you add chlorine to a pool. The difference is that in a saltwater pool, hypochlorous acid constantly recombines with the sodium in the water and turns back into salt. Salt does not evaporate, so there is no need to regularly add more salt or chlorine to the system. These systems typically do not experience chloramine buildup like traditional pools.

Pros and Cons of Salt Water Systems

Saltwater pools are usually softer on the skin and easier to maintain. However, they do have some downsides as well.

Advantages of Saltwater Pools

Lower Annual Costs

Saltwater pools are much more budget-friendly than traditional chlorine pools. For a summer supply of salt, The Home Depot estimates the cost to be between $20 to $30 on average. On the other hand, chlorine will cost around $150 to $180 for the same period and the same size pool.

Saltwater pools have a high start-up cost, but it’s easier to maintain after this initial expense. Therefore, it is cheaper in the long run.

Saltwater Pools are Gentler

Saltwater pools are more gentle on the skin, eyes, swimwear, and hair due to the lower chlorine content. They also don’t have the traditional heavy chemical smell many people dislike about chlorine pools.

Maintains Body Moisture Balance

Most people will be familiar with the drying effects on the skin after spending some time in a traditional chlorine pool. However, a saltwater pool will help keep your body moisture balance and won’t strip your body and hair of natural oils. The water is softer and will leave you feeling nice and silky after a swim.

Better for the Environment

In addition to benefiting your overall health, saltwater pools are also better for the environment. Traditional chlorine pools give off chloramines, which emit gas into the environment. On the other hand, while saltwater pools do have some level of chlorine, the level is definitely not as environmentally detrimental.

No Need to Store Chlorine

Chlorine is a dangerous chemical and can be a pain to store – especially if you have pets and children around. With a saltwater pool, there’s no more need to think about the dangers of storing chlorine and ensure you store it properly at all times. Instead, the saltwater chlorinator will do the job for you by converting salt into chlorine.

Disadvantages of Saltwater Pools

Higher Initial Cost

It is expensive to start up a saltwater pool. Salt chlorine generators start at about $400 and cost around $2,000 to install. However, operating costs are usually low in the long run unless you have to replace the salt cell. Salt cells typically last anywhere from three to seven years. It can be challenging to compare the costs of a traditional pool and a saltwater pool because you will need a reasonable estimate of the price of chemicals. Check out my saltwater pool cost guide and swimming pool maintenance cost guide for more info.

Corrosion

Corrosion is the other major downside. To avoid corrosion, I recommend using equipment specifically designed for salt water pools. And use zinc anodes, which will prevent metallic equipment from corroding in the pool water. The pool plaster lifecycle for an inground pool filled with salt water is only a few months shorter than a chlorinated pool. But with proper care, you will be able to maximize the life of your plaster. The saltwater does not affect a fiberglass pool.

The biggest corrosion issue from saltwater happens outside the pool. Most decking is not resistant to salt water and will take a beating when pool water splashes out or drips from swimmers. Some types of decking are more vulnerable than others.

For a more in-depth comparison, read my salt water vs. chlorine pools guide. You can also choose between salt water and mineral pools or salt water and ozone pools, which I’ve written complete comparisons on as well.

Are Salt Water Pools Safe?

Yes. Because the salt water chlorinator generates the same levels of chlorine found in a traditional pool, there is no difference in the sanitizing power. The only exception is when stabilizer levels are not kept high enough. Hypochlorous acid is not a very stable chemical and breaks down quickly in the sun. Because of this, you will need to maintain adequate stabilizer levels in a salt water pool.

In some ways, saltwater pools are even safer than chlorinated pools. Saltwater pools do not produce chloramines, a chemical commonly found in traditional pools that can irritate the skin and eyes. And in general, saltwater pools require fewer chemicals.

Are Salt Water Pools More Expensive or More Difficult to Own?

Salt water pools are more expensive to start. However, over time the cost may even out. The main expenses involved in starting a salt water pool include the purchase of the salt cell and pump and the pool salt itself. The salt cell needs to be replaced in 3-7 years, costing $300-$800. However, the life of the salt cell is dependent on how much it is used. Read my full saltwater pool cost breakdown for a more in-depth look.

Saltwater pools are usually easier to own and maintain. They require the same testing as traditional pools, but the system is more contained. Generally, if the chlorine levels in the pool are inadequate, all that is required is adjusting the settings on the control box. Other chemicals used in traditional pools may also need to be used in saltwater pools.

Typical Lifespan of a Saltwater Pool

Chlorine is generated slowly over time, wearing down the titanium in the cell. This process means that the salt cell will eventually need replacing. With regular maintenance, the average lifespan of a salt cell is three to seven years. If you regularly replace the salt cell, your saltwater pool should last as long as a chlorine pool.

Design Considerations for Saltwater Pools

There are many options when it comes time to designing your saltwater pool. However, due to the natural chemical properties of salt, there are things to consider when building a saltwater pool.

The size of the pool should complement and enhance your existing space and the natural features of your backyard.

Saltwater pools are very flexible in design, meaning you don’t have to go with the traditional rectangular or circular design you often see with conventional pools.

Some other things to consider are the materials used around the pool. Salt may leave a white residue when splashed out, so consider lighter-colored stone or a non-metal material and natural-looking landscaping such as rock formations and trees.

What Kind of Maintenance Does a Salt Water Pool Require?

The main maintenance tasks for salt water pool owners are testing and washing the salt cell. Water testing is still required because chlorine is only one parameter that needs to be controlled to maintain a healthy pool. If the pH level or another parameter is not where it should be, adding certain chemicals and shocking your saltwater pool may be necessary to balance the system.

Cleaning the salt cell is only required if you find a scale (mineral residue) on it during a regular maintenance check. You should do these checks every three months. It is easy to remove the scale with a plastic or wooden tool or a quick rinse in diluted acid.

You also need to keep an eye on your salt levels. Use my salt calculator to figure out how much salt to add or water to replace to get into the ideal range. You’ll need to adjust salt levels when you open your saltwater pool as well.

Salt water pools can also turn green if you don’t take care of them. Check out my article linked there for my process of how to fix it.

How Much Salt Does My Swimming Pool Need?

Before calculating how much salt to add to your swimming pool, you will need to calculate the volume of the pool. Once you have figured this out, you want to add 2700-3400 ppm. Shoot for somewhere in the middle, around 3200 ppm. Test your water using a saltwater testing kit or check your salt chlorine generator to determine the salt levels in the pool. If you added too much, head over to my guide on how to lower the salt level in your pool for tips on what to do.

What is a Salt Chlorine Generator?

Salt chlorine generators use electricity and dissolved salt to convert sodium chloride, or table salt, into chlorine for your pool. This process is called electrolysis, which is when a chemical is broken down into its components.

In the case of a salt chlorine generator, electrolysis occurs when the salt water passes through the salt cell’s plates, which are coated with ruthenium or iridium. The control board charges these metal plates, which then break down the salt into chloride ions that combine to turn into chlorine gas. Finally, when the chlorine gas enters the pool water, it turns into hypochlorous acid, which sanitizes the pool water just like traditional pool methods. This hypochlorous acid eventually turns back into sodium chloride and goes through the electrolysis process again. Since the salt is recycled repeatedly, it makes saltwater pools that much cheaper to maintain in the long run.

What Kind of Salt to Use in a Saltwater Pool

The main thing to look out for in the salt you use in your pool is purity. Make sure to use salt at least 90-95 percent sodium chloride, and stay away from food-grade iodized salt. You can use solar-evaporated or machine-evaporated sea salt, but the purest form of sodium chloride comes from mined salt. It is purer because bacteria and microorganisms found in the ocean will not mix with the salt.

What Kind of Filters Do Salt Water Pools Use?

The salt cell in a saltwater pool is not responsible for filtration. This job belongs to an ordinary pool filter that connects to the salt generator system. You can use most pool filters with saltwater systems, including sand filters, cartridge filters, and diatomaceous earth filters. Each has advantages and disadvantages. One important thing to remember is that the filter will need to run a lot because the pool will only generate chlorine when the filter is on.

How Do You Winterize a Salt Water Pool?

Saltwater pools have a few unique issues when it comes to winterizing. The first is that the sensors on the salt system can give inaccurate salinity readings when the water gets too cold. And most systems are calibrated to shut down at around 50-59 degrees F because the readings are faulty.

This issue isn’t a problem for most people because the pool is not used in the winter, or the water temperature is maintained at a higher level. But if you plan to use the pool when the water temperature is below 50-59 degrees F, you will need to find another source of chlorination.

Winterizing a saltwater pool is very similar to winterizing a traditional swimming pool. You should carefully balance the water and make sure to disconnect, drain, and store the filter and salt system for the winter. Read my full article on how to winterize a salt water pool for all the steps.

Can You Heat a Salt Water Pool?

Of course! All of the heating options for traditional chlorine pools are available for salt water pools too. You can read my article on heating a salt water pool for more information.

Is a Salt Water Pool Right For You? Factors to Consider

When choosing a saltwater or a chlorinated pool, you must weigh the pros and cons and ultimately make the best decision for your situation. Whether considering a new pool or converting over your current pool, each option has benefits and drawbacks.

Why You Might Want a Saltwater Pool

  1. Saltwater systems may be safer. While there are arguments over whether the pool water itself is safer when a saltwater system is used, there is no doubt that handling salt is safer than handling chlorine.
  2. Saltwater may be easier on the skin and eyes. Some people are extremely sensitive to this, while others don’t really notice.
  3. There will also be less chlorine smell because of the lower chlorine levels in a saltwater pool.

Why You Might *Not* Want a Saltwater Pool

  1. Saltwater is incompatible with certain types of equipment and fixtures. This incompatibility means that the expense of retrofitting an existing pool for a saltwater system is a significant consideration and may not even be possible.
  2. The saltwater system itself is expensive and does not replace the cost of many other pool chemicals, such as those used for balancing pH and alkalinity.
  3. Salt generators do not entirely replace chlorine because cold weather makes them inefficient. This fact means that winter pool maintenance usually has to be done using an alternative source of chlorine.

Need Help Building Your Pool?

I offer design consulting services to help you build your ideal pool. I'll work with your contractor, create build-ready designs and specs, and much more.

Is Saltwater the Right Choice for You?

The major disadvantage of a saltwater system lies primarily in its upfront cost. Therefore, many suggest that if you can afford a saltwater system, you should invest in one. However, there is also personal preference to be taken into account. If you have maintained a traditional chlorine pool for years and are comfortable with it, you may not want to switch. Conversely, if you or your family struggle with reactions to chlorine, it may be a perfect choice.

If you have any questions about salt water pools, don’t hesitate to ask!

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