7 Alternatives to Chlorine for Your Swimming Pool


For years, chlorine has been one of the most common water treatments for pools. Because chlorine is such an effective yet inexpensive disinfectant, many pool owners use chlorine to sanitize their pools. In recent years, however, chlorine has become quite unpopular due to its side effects, including its strong chemical smell and its burning sensation in swimmers’ eyes and skin. If you’re one of the many pool owners looking to stop using chlorine, you may be interested in alternatives to chlorine for your swimming pool.

There are a number of alternatives to chlorine for swimming pools. Such alternatives include bromine, ionizers, salt water, ozone generators, mineral systems, PHMB, and non-chlorine shock. Each one of these alternatives has its benefits and its drawbacks. 

If you’re interested in giving one of these alternatives a try, read on! Today, we’ll cover the 7 alternatives to chlorine for swimming pools and how to use them.

1. Bromine

Bromine has become one of the most popular alternatives to chlorine for swimming pools for a number of reasons. In addition to being an effective disinfectant, this substance will keep pool water stabilized with little maintenance involved. Thus, you can enjoy a crystal clear pool without the hassle of constantly adjusting the bromine levels.

Although bromine is in the same halogen chemical family as chlorine, it is known to be less irritating on the skin. Those who suffer from allergic reactions to chlorine often benefit from using bromine instead. Keep in mind that bromine can still have a strong smell in swimming pools. If you’re looking for an odorless alternative to chlorine, bromine may not be the solution for you.

The main disadvantage of bromine is its ineffectiveness in sunlight. Similar to chlorine, bromine will burn away when exposed to UV rays. However, chlorine can handle direct sunlight much better than bromine, as it is more protected than bromine is. For this reason, bromine is not the best disinfectant for outdoor pools.

Advantages to Bromine

There are a number of benefits to using bromine as an alternative to chlorine. Perhaps the greatest of these advantages is its gentleness on swimmers’ skin and eyes. Unlike chlorine, which is known to burn eyes and dry out skin, bromine has little effect on swimmers. For this reason, many people who experience allergic reactions to chlorine find bromine as a safe alternative.

Another benefit to bromine is its ability to stabilize water for long periods. Unlike chlorine that requires constant maintenance, bromine requires few adjustments. Once bromine is added to your pool, there is little need to test the water, as it will remain stable for longer periods than chlorine.

A final benefit of using bromine is that it remains effective even in high temperatures. Because bromine keeps water balanced as the temperatures rise, bromine is a popular sanitation option for spas. Additionally, many pool owners use bromine for their indoor pools.

Disadvantages to Bromine

Unfortunately, there are some disadvantages to using bromine in pools. Although bromine is effective at keeping water stabilized in high temperatures, it becomes ineffective when exposed to UV rays. Because sunlight will eat away the bromine, it is often necessary to increase the dosage of bromine in your pool. This, however, can create a strong odor that can be just as irritating as chlorine.

Another disadvantage of bromine is its expensiveness. While it may be safer to use than chlorine, it can cost up to twice as much as chlorine. Additionally, you may end up spending money on additional chemicals to keep the pool sanitized when exposed to direct sunlight.

Finally, bromine is not a preferred option for outdoor pools. Although it is extremely effective in high temperatures, it simply cannot handle the UV rays from the sun. Thus, if you are looking for a disinfectant for your outdoor pool, bromine may not be the best option for you.

2. Ionizers

The next alternative to chlorine is ionizers, a device that uses a low-voltage DC current to send copper and silver into the water. Because copper is an algaecide and silver is a sanitizer, this positive charge will attract bacteria, algae, viruses, oil, and other unwanted substances. It will then clump them together, allowing the compounds to be carried to the filtration system.

Because this technology lacks an oxidizer, a small amount of chlorine or bromine may need to be added to the water. Additionally, ionizers depend on moving water to properly sanitize the pool. The pool pump must remain running if you want the ionizers to function.

Advantages to Ionizers

The advantage to using ionizers rather than chlorine is that it doesn’t cause eye irritation or dry skin. Those who experience allergic reactions to chlorine will find ionizers to be a much safer and gentler option for sanitizing pools. Moreover, ionizers reduce the smell of chlorine in outdoor and indoor pools.

If you don’t mind using chlorine in your pool, ionizers are known to operate better when added with chlorine. By combining chlorine and ionizers together, you can increase the water quality in your swimming pool.

Disadvantages to Ionizers

Although ionizers are effective at filtering unwanted substances such as bacteria, they cannot function without the use of chlorine or bromine. Because many pool owners choose ionizers as an alternative to chlorine, it is a disadvantage that they require chlorine to operate.

Another disadvantage to ionizers is that you must leave your pump running in order for ionizers to work. While it is a good idea to let your pool pump run at least 8 hours a day, there may be times you wish to turn it off. Unfortunately, whenever your pump stops running, the ionizers will stop sanitizing the water.

Because ionizers operate using copper and silver, they may lead to metal buildup in your pool. Not only can this damage the equipment, but it may make the hair and fingernail beds of swimmers turn green. To ensure your water is properly balanced, it is important to regularly test the water when using ionizers.

A final disadvantage to ionizers is the cost. The cost of ionizers is much more expensive than the cost of chlorine. Additionally, your pool’s running costs may increase since you’ll need to run the pump continuously.

3. Salt Water

If you’re looking for a safe, natural alternative to chlorine, salt water may be the perfect solution for you. Unlike chlorine, saltwater does not irritate the eyes and is healthier for the skin. Additionally, saltwater pools eliminate the strong odor associated with chlorinated pools.

Although saltwater pools were once reserved for only luxurious resorts, they have become an increasingly popular option for backyard pools. Saltwater pools provide powerful sanitation and soft water without the need for harsh chemicals. While they do require some maintenance, saltwater pools can promote water clarity just as well as traditionally chlorinated pools.

Advantages to Saltwater Pools

In recent years, pool owners have become increasingly concerned about the use of harsh chemicals in their backyard pools. Because chlorine is known to burn eyes and dry out skin, many people are searching for a safe alternative for their pools. For this reason, saltwater pools are an excellent option for both indoor and outdoor pools.

Because saltwater eliminates the need for chlorine, there is no strong chlorine smell in saltwater pools. Furthermore, saltwater pools do not irritate the eyes or skin, which consequently improves your swimming experience.

Disadvantages to Saltwater Pools

When considering installing a saltwater pool, it’s important to understand that saltwater still requires certain chemicals to function. Many of these chemicals are the same chemicals you’d add to a chlorinated pool.

In order for a saltwater pool to function properly, it will need regular maintenance. Because saltwater pools operate using salt cells, it’s important to occasionally clean the cells. Even with regular maintenance, these cells will need replacing approximately every five years.

4. Ozone Generators

Pool owners looking to reduce the amount of chlorine in their pools may benefit from installing ozone generators. Ozone generators are machines that attach to the pool’s filtration plumbing line. Once installed, it inserts an active form of oxygen known as ozone gas into the swimming pool. As a result, the ozone gas will react with any impurities to promote clean water.

The two types of ozone generators are ultraviolet light and corona discharge. The ultraviolet light, which is a low-pressure vapor lamp, is installed directly to the water return line. Whenever pathogens float by the system, the UV light generator will create ozone. Corona discharge generators, on the other hand, use an electrical arc to create ozone. Once again, the ozone is what destroys pathogens that float by the system.

Ozone generators are becoming increasingly popular for a number of reasons. In addition to reducing chlorine usage, Ozonators make pool water softer and more enjoyable to swim in. Besides the high price, there are very few drawbacks to installing an ozone generator for your pool.

Advantages to Ozone Generators

There are numerous advantages to installing an ozone generator for your swimming pool. One of the greatest benefits is that it reduces the amount of chlorine used. In fact, Ozonators can reduce chlorine usage by up to 90 percent. Additionally, ozone generators use very little electricity. 

Although ozone generators are most commonly installed as an alternative to chlorine, they may also be used to soften your pool’s water. Because ozone generators are pH neutral, you don’t have to worry about them making pool water unbalanced. Furthermore, Ozonators may help get rid of calcium scaling and other issues in your pool water.

A final benefit to ozone generators is their effectiveness at reducing organic contaminants in the pool. By installing an ozone generator, you can eliminate bacteria and other unwanted substances while avoiding using high amounts of chemicals.

Disadvantages to Ozone Generators

Although ozone generators can reduce chemical usage by up to 90%, it isn’t possible to avoid chemical usage completely. Because ozone generators cannot sanitize the pool on their own, it is necessary to use an Ozonator in conjunction with a sanitizer. Many pool owners find it easiest to use Ozonators along with their traditional chlorine setup.

Another downside is the cost of ozone generators. They are one of the most expensive alternatives to chlorine for swimming pools. However, because they reduce the number of chemicals used in pools, many pool owners find them to be a great investment.

5. Mineral System

As one of the simplest alternatives to chlorine, mineral systems are excellent options for sanitizing swimming pools. Although they still require chemicals to operate, they can reduce chlorine usage by up to 50 percent. They are incredibly easy to operate and require very little maintenance.

The main purpose of mineral systems in pools is to eliminate bacteria and algae growth in the water. By controlling algae and bacteria, mineral systems can greatly reduce the amount of chlorine needed to keep the water sanitized.

While the price for a mineral system may seem expensive, mineral systems will save you a significant amount of money in the long run. In addition to lowering chemical usage, mineral systems are low-maintenance and last for years.

Advantages to Mineral Systems

Operating a mineral system is extremely easy. Once a mineral system is installed, very little maintenance is necessary for keeping pool water sanitized. Although you will need to add chemicals, you will use far less chlorine than a traditional chlorine setup.

Mineral systems are effective at not only keeping pools clean but also softening the water. Many mineral systems combine minerals and salt to improve water quality. Moreover, mineral systems control bacteria and algae growth and thus eliminate the need to use harsh chemicals.

Disadvantages to Mineral Systems

While mineral systems may be an alternative to chlorine, this does not mean you can avoid using chlorine entirely. Chlorine will need to be added to sanitize the water as well as balance the pH levels. In addition to chlorine, you may need other chemicals to keep a proper pool water chemistry.

Mineral systems also tend to cost more than traditional chlorine setups. With that being said, mineral systems may ultimately save you a significant amount of money since you won’t need as many chemicals. Additionally, they require little maintenance, making them a worthwhile investment if you don’t mind paying the initial cost.

6. PHMB

Polyhexamethylene biguanide (PHMB) is perhaps the best alternative to chlorine if you want to completely avoid using chlorine as a sanitizer. PHMB cleans pools by causing bacterial cell walls to burst. It then wraps the bacteria in a heavy gel, allowing it to sink to the bottom of the pool. As a result, bacteria will be removed from the pool whenever you run your pool vacuum.

PHMB is a very low-maintenance alternative to chlorine that is gentle on the skin, eyes, and hair. In addition, PHMB does not need a stabilizer since it can handle UV rays.

Advantages to PHMB

The greatest advantage to using PHMB is that you can avoid using chlorine in your pool. As a result, you won’t need to worry about pool water burning your eyes or irritating your skin. What’s more, PHMB eliminates the strong smell of chlorine to improve your pool experience.

Unlike chlorine, PHMB does not burn away when exposed to sunlight. Thus, you won’t need chemical additives such as a stabilizer. PHMB is also very low-maintenance and easy to use.

Disadvantages to PHMB

The only disadvantage to PHMB is the price. PHMB tends to be more expensive than chlorine, but it is worth it in the long run. Because PHMB requires little maintenance, you will end up saving more money than you would with a chlorinated pool.

When switching from a chlorinated pool to PHMB, it’s important to first drain the entire pool. Because PHMB is incompatible with chlorine, you’ll also need to thoroughly rinse any swimwear that has traces of chlorine on it.

7. Non-Chlorine Shock

The final alternative to chlorine for swimming pools is a non-chlorine shock. The non-chlorine shock will handle certain pollutants such as body oil and sunscreen to promote water clarity. Unfortunately, it cannot sanitize your pool, and consequently requires chemicals to keep pool water clean.

Advantages to Non-Chlorine Shock

A non-chlorine shock is effective for burning away dead organic matter. It is also cost-effective, making it an excellent option if you’re looking for an inexpensive alternative to chlorine.

The non-chlorine shock is especially beneficial for indoor pools and spas. By burning dead organic matter, the non-chlorine shock can greatly improve your swimming experience.

Disadvantages to Non-Chlorine Shock

Unfortunately, the non-chlorine shock cannot sanitize water on this own. Many pool owners end up combining non-chlorine shock with chlorine and other chemicals. You may also use non-chlorine shock with bromine and mineral systems, which all require some amount of chlorine.

Because sunlight will also oxidize dead organic matter, a non-chlorine shock is not very effective for outdoor pools. If you own an outdoor pool, it may be best to choose a different option for sanitizing pools.

Jed Arnold

Jed spent every year from the ages of 15 - 22 as a Lifeguard (Red Cross) and ages of 17 - 22 as a Certified Pool Operator (CPO). Between working for over a dozen facilities and owning a pool, he carries over a decade of pool experience.

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