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Chlorine Alternatives for Swimming Pools

Chlorine is the most common sanitizing choice for pool owners, but is it the best? Chlorine and chloramines have long been blamed for causing red eyes and skin irritation for swimmers, motivating some pool owners to look elsewhere for their sanitation needs. But which chlorine alternative is best? And what's the difference between the different types of sanitizers?

It's actually a question we hear a lot. But a lot of it comes down to personal preference, benefits offered, and ease of maintenance. To help you make the right choice for your pool and lifestyle, we've put together this informational guide to teach you more about the most popular alternative sanitizers.


Salt Chlorine Generator

Salt has become very popular as an alternative way to generate and maintain chlorine levels, providing an enjoyable swimming experience. Pool salt systems use salt in the pool water to generate chlorine through the process of electrolysis. Salt water passes through a salt cell where it receives an electric charge, converting it into chlorine. It does this consistently to keep the free chlorine level steady, and chloramines low.

Free chlorine is what keeps your water clean, clear, and sanitized. High chloramine levels are the real reason you hear about skin irritation and the “chlorine smell.” If your pool smells like chlorine, there’s a good chance that it actually needs MORE chlorine. This is what makes salt water pools so desirable. Low chloramine levels with a balanced salinity level will provide comfortable water that does not irritate the skin or eyes, and it won't smell. Salt is usually cheaper than other pool chemicals. But keep in mind, salt cells need occasional cleaning to prevent calcium buildup, and do not last forever. Expect to replace your salt cell about every 5 years.

salt chlorine generator

More information:

  • Powerful water sanitation
  • Creates soft-feeling water
  • No more buckets of chlorine
  • High initial investment, low maintenance cost
  • Salt cell will need replaced every 3-5 years


Ozone Pool System

Ozone systems provide clean, clear, and safe water for your pool, while significantly reducing chlorine requirements by 60-90%. This sanitizer also removes eye and skin irritants from pool water. Sounds like a safe bet to us! Ozone generators are designed with a highly reliable cell that can last up to 5 years before replacement is needed. If you are looking for the most scientifically advanced pool water sanitation, an ozone sanitizer system is the optimal choice for residential pools. 

pool ozone system

More information:

  • Powerful water sanitation
  • Creates soft-feeling water
  • Reduces the amount of chemicals
  • Prevents calcium scaling on surfaces and equipment
  • pH neutral
  • High initial investment
  • Used in combination with a residual sanitizer


Mineral Pool System

Mineral pool systems are alternative sanitizers that are very easy to maintain, and can reduce chlorine use by up to 50%. These systems automatically feed small amounts of copper and silver ions, a long-acting natural sanitizer, into the pool to create soft and clean water. Maintenance is simple with the pre-filled cartridges. These charged ions are not the same thing as having copper and other metals in your pool, meaning mineral systems cannot cause staining effects on pool surfaces.

Mineral systems have a lower initial investment cost than a salt chlorination or ozone system, but the mineral cartridges require more frequent replacement – about every 6 months. They also require some residual chlorine in the water, about 0.5-0.6 ppm, to help with organic material in the pool.

pool mineral sanitizer

More information:

  • Very low maintenance
  • Creates soft-feeling water
  • Cuts chlorine use up to 50%
  • Controls algae and bacteria
  • May have a high initial investment, depending on system


Bromine Tablets

Bromine is typically used in spas and indoor pools as a chlorine alternative. This is because bromine does not include CYA, which protects chlorine against “burning-off” from the sun's harsh UV rays. Since indoor pools and spas are often covered from sunlight, CYA is not as important. Bromine can be more costly for outdoor pool owners, potentially raising the cost of chemicals since it is more expensive than chlorine and it's needed more often.

The good news is that bromine is more stable than chlorine in warmer temperatures, again making this sanitizer the premiere option for hot tub and spa owners. Pools that are sanitized with bromine do not require as much testing, meaning the water stays balanced for a longer period of time.

bromine tablets

More information:

  • Great for hot tubs, spas, and indoor pools
  • More stable than chlorine in high temperatures
  • More expensive than chlorine tablets
  • Reduces skin irritation and red eyes
  • Not stabilized against UV rays


Non-Chlorine Shock

Non-chlorine shock treatment is great chlorine alternative for oxidizing organic pollutants, such as body oils, sunscreen, and urine. Unfortunately, non-chlorine pool shock can’t sanitize the water on its own. Non-chlorine shock still needs an additional sanitation method, such as chlorine, to sanitize a pool.

Oxidizing the organic pollutants helps keep chloramine levels low so free chlorine can work effectively. Non-chlorine shock is great for indoor pools or pools with a high bather load.

Sunlight will help oxidize organic pollutants naturally, so non-chlorine shock is popular for indoor pools that have little-to-no sunlight. Non-chlorine shock is also used in hot tubs to oxidize (burn up) dead organic matter. This allows the sanitizer to destroy harmful microorganisms such as bacteria and algae.

leslie's fresh 'n clear non-chlorine shock

More information:

  • Great for hot tubs and indoor pools
  • Safe to swim immediately after application
  • Requires a residual sanitizer
  • Higher price than chlorine shock
  • Safe to use with chlorine, bromine, and mineral systems


In addition to the alternative sanitizers listed above, there are also other ways to keep your pool sanitary. UV sanitizers use UV light to sanitize water, and are sometimes used in conjunction with ozone systems. There's also another type of sanitizer chemical called biguanide. However, it's not as popular as other sanitation methods, is incompatible with certain types of pool chemicals, and may require regulatory clearance for use in certain areas of the country.

If you need help deciding between chlorine alternatives or want to learn more about how they're used in the pool, we can help. Stop by your local Leslie's store to speak with one of our pool experts, or give us a call at 1-800-LESLIES.