Is a Chemical Free Pool Possible?

Written by Michael Dean
June 14, 2023

swimming pool with no chemicals

Traditional chlorine pools can be complicated and costly, not to mention the chemicals can be harmful to vulnerable swimmers. A chemical-free pool may sound like a crazy idea, but they are a great alternative if you want to cut out chlorine from your pool. They can be clean, cheap, easy to maintain, and are a great alternative for swimmers with skin irritation issues. However, chemical-free pools require a lot of upkeep and maintenance to ensure they are safe for swimmers.

In this article, I will discuss chemical-free pools in-depth, including how they work, how to maintain them, safety concerns, maintenance costs, and more!

Main Takeaways

  • The safest alternative to a traditional chlorine pool is a mineral pool, which requires fewer chemicals.
  • Chemical-free pools can use several systems, including ozone, UV, advanced oxidation processes, and natural swimming pools.
  • While it is possible to have a chemical-free pool, most pool owners use small amounts of chlorine alongside chemical-free methods to clean the water.
  • Untreated swimming pools can be very dangerous for swimmers, “chemical-free” refers to alternative sanitizers, not NO sanitizers.

What Are Chemical-Free Pools?

A pool without chlorine may seem like a recipe for disaster, but if managed right, a chemical-free pool can be a natural and healthy way to enjoy a swim. Chemical-free pools are not a cesspool of algae and bacteria but are sophisticated systems designed to keep your pool water clean without using harmful chemicals.

Don’t worry. To build a chemical-free pool, you don’t just fill a hole with water and hope for the best! Chemical-free pools use alternative sanitation methods, so instead of cleaning the water with chlorine, the water is cleaned with a combination of filtration and natural water purification methods. There are several different types of chemical-free pools that I will cover below, but one thing they all have in common is the lack of chemicals such as chlorine or bromine.

Why Use A Chemical-Free Pool?

Anyone who has spent time in an overly-chlorinated pool knows it’s unpleasant on your eyes and skin. Unfortunately, that’s not the worst potential problem. Several studies show that exposure to chlorine in a pool can dramatically reduce lung function. The issues are especially pronounced in indoor pools but can occur anywhere near a chlorinated body of water.

Ultimately, while chlorine can keep your pool germ-free, you’re exposing everyone who swims in it to potential health problems. People with skin sensitivity issues may get rashes from chlorine pools, so seeking an alternative may be their only chance to have a swimming pool.

A Closer Look at How a Chemical-Free Pool Works

Here are the different systems that can be used to sanitize chemical-free pools. Chemical-free pools need an effective filter system to remove harmful bacteria, debris, and contaminants. A good filtration system will make it much easier to sanitize the water without chemicals. These systems work well at killing off water-borne contaminants, but they are designed as supplemental treatments alongside additional water treatment methods. Most pool owners still use small amounts of chlorine (around 0.5 ppm) when using these methods.


Ozone is a powerful, naturally occurring sanitizer commonly used in food processing plants and can be found in the Earth’s atmosphere. Ozone works by oxidizing and breaking down contaminants in the water, such as bacteria, viruses, and organic matter. Ozone gas is an oxygen molecule produced by passing oxygen through a high-voltage electrical discharge. There are three oxygen atoms in ozone, so when an ozone molecule comes into contact with a contaminant, the extra oxygen atom breaks off from the rest forming O2 with the remaining oxygen atoms.


Ultraviolet (UV) is a very common water sanitation method used in water treatment facilities and pools. It works by emitting a UV-C light radiation that water passes through, which alters the DNA of living pathogens, preventing them from reproducing and effectively destroying them. That said, UV does not oxidize the water and is better suited as a secondary sanitizer rather than your primary sanitation method.

Advanced Oxidation Process (AOP)

Advanced Oxidation Processes (AOP) use both ozone and UV to oxidize and break down contaminants. 

AOP used for pool water sanitation combines ozone and ultraviolet light, which produces hydroxyl radicals that can quickly react with and destroy organic and inorganic contaminants, including bacteria and viruses. 

AOPs are becoming increasingly popular with pool owners who want an alternative sanitation method. AOPs are effective, efficient, and may lower your overall maintenance costs.

Natural Swimming Pools

Natural swimming pools are a very unique type of pool that uses entirely natural methods to maintain your pool. Instead of sanitizing your water with chemicals or alternative processes, natural pools use organic plants to naturally filter and clean the water. Natural swimming pools have a section of the pool dedicated to growing various water-based plants. This section acts as the pool’s “filter.” The water flows through the filter section containing plants, aggregates, and other filtering methods.

How to Maintain a Chemical-Free Pool

No matter what kind of chemical-free pool system you invest in, I cannot stress enough how important it is to maintain it. The most important things to stay on top of in pool maintenance are filtration, circulation, cleaning, and chemistry. Let’s take a closer look at these important maintenance tasks.


If you plan to use less chlorine in a pool, your filter becomes one of the most important lines of defense in a pool. Your pool filter filters out algae and other debris from your pool water, so it is important to clean your filter often and ensure the filter is functioning properly. If you use fewer chemicals in your pool and your pool’s filter is not working properly, your water will quickly become unsafe to swim in.


Without your pool pump circulating the water, your chemical-free pool will become stagnant and essentially turn into a murky pond full of algae and bacteria. While I recommend owners of traditional pools run their pumps for 8-12 hours per day, chemical-free pool owners should run their pumps for up to 18 hours a day to ensure the water does not stagnate.


You must be vigilant in your cleaning schedule if you decide to have a chemical-free pool. Without chlorine, your chemical-free system will struggle to kill off contaminants by itself. So, you should brush, vacuum, and skim your pool frequently to prevent bigger problems from arising. In theory, your chemical-free sanitizer systems should only be killing off small amounts of bacteria and algae, while your filter and pool vacuum do the bulk of the work.


Look, I know we are talking about “chemical-free” pools, so why do I bother bringing up chemistry? Well, most pool owners who opt for a “chemical-free” system still use some chemicals. There are many important chemical levels to track in a pool, such as pH, alkalinity, and calcium. Even in natural swimming pools, it is extremely important to frequently test your chemical levels to ensure the sanitizing system works properly. As I mentioned above, many pool owners who opt for chemical-free systems still use small amounts of chlorine as a safety net. In this case, I guess we can call chemical-free pools “low-chemical” pools.

If your chemical-free pool has a major algae infestation and needs a major cleaning, I recommend shocking the pool. This is the only way to quickly kill algae and bacteria in your water.

Are Chemical-Free Pools Safe?

Chemical-free pools can definitely be a safe alternative to chlorine pools. As I mentioned above, chlorine can irritate the eyes and skin of swimmers and may produce chloramines which are a potentially dangerous by-product of chlorine and contaminants in a pool. If you maintain your chemical-free pool well and prevent bacteria, viruses, and algae from infesting your water, your pool can be a safe swimming spot.

That said, when it comes down to it, the safest way to ensure your pool water is clear of algae, bacteria, and viruses is to use chlorine or another chemical sanitizer. While it is definitely possible to sanitize your pool with alternative methods or build a natural pool, you run more of a risk of algae infestations or other harmful bacteria entering your pool water.

Dangers Of An Untreated Swimming Pool

Harmful bacteria or parasites such as E-coli, cryptosporidium parvum, and legionella can thrive in untreated pool water. So, it is important to distinguish that when I refer to chemical-free pools, I am not referring to untreated pools but rather pools that are treated and sanitized in an alternative way. In fact, many pool systems marketed as chemical-free do, in fact, use chemicals. However, they use a much smaller dosage of chemicals than traditional pools.

Untreated pool water can have disastrous effects on swimmers and, in some cases, can be fatal. It is important to ensure that your chemical free is still treated in accordance with the EPA.

What Is The Healthiest Pool System?

While chemical-free pools have less of a chance of irritating your skin than traditional pools, these pools are much more likely to house dangerous bacteria and algae. The safest and healthiest type of swimming pool is a mineral pool. Mineral pools are the best of both worlds. While they still contain some chlorine, the amount is much less than a standard pool (0.5 ppm as opposed to 1-3 ppm). These pools sanitize your water using the natural properties of silver and copper to kill bacteria and algae in your water. Mineral pools are better for your skin and have a softer feel than traditional pools. Mineral pools aren’t technically “chemical-free,” but they use far fewer chemicals than saltwater or traditional pools, ensuring the water is algae and bacteria-free.

Keep in mind that mineral pools are difficult to maintain and require a lot of knowledge and maintenance to function correctly. I do not recommend a new pool owner without any experience maintaining a pool attempt to switch to a mineral pool.

How Do Chemical-Free Pools Compare to Other Types of Pools?

Here are some of the other common types of sanitation methods and how they compare to chemical-free pools.

Traditional Chlorine Pools

We’ve all experienced that burning irritation from swimming in a pool with too much chlorine. Red eyes, bleached hair, itchy skin, and other unwanted maladies quickly ruin the fun. What is chlorine, anyway, and why does it cause these problems?

Chlorine is the most popular chemical for pool cleaning. It is VERY effective at killing germs in personal pools, public pools, and venues such as water parks. While chlorine effectively removes germs, it also has an unwanted side effect.

Chlorine binds with human waste, such as sweat and urine. Binding creates new chemicals called chloramines. These chloramines are the main cause of problems. Along with dichloramine and trichloramine, they create a gas that rises from the water into the air. It’s this gas that irritates the skin, eyes, and lungs.

According to the CDC, most health departments across the nation limit the amount of combined chlorine in a pool to 0.4 ppm or less. Achieving the correct balance is difficult and depends to a certain extent on the number of people in the pool.


  • Very effective at neutralizing contaminants
  • Easier to maintain than other options
  • Chlorine shock is the best way to kill off major algae infestations


  • Can produce harmful chloramines
  • May irritate the skin and eyes of swimmers

Saltwater Pools

It’s easy to understand why many people want to stay away from chlorinated pools. One popular alternative is a saltwater pool. As the name suggests, these pools use salt water instead of fresh water. They still contain chlorine, but the system from which the chlorine is produced is different, and the water is generally less concentrated and less irritating. While a saltwater pool is better for your health than a traditional one, it’s often too expensive and too complicated for most homeowners.


  • They require low levels of chlorine
  • You don’t need to store a large number of chemicals at your house
  • The saltwater has a soft feel that some people like


  • Typically more expensive than traditional pools
  • Can require the same amount of maintenance as chlorine pools
  • The saltwater content of your pool also limits the types of materials you can use on the lighting, fixtures, masonry, and more

I cover more details in my saltwater pools vs. traditional chlorine pools comparison.

Biguanide Pools

If you’re looking for an alternative to chlorine or saltwater pools, you might want to consider a biguanide pool. Biguanide pools use a non-chlorine sanitizer called polyhexamethylene biguanide (PHMB) to keep the water clean and clear. PHMB is a liquid sanitizer added directly to the water and kills bacteria and other microorganisms on contact. Biguanide pools are gentler on the skin, hair, and eyes than chlorine or saltwater pools. And since biguanide doesn’t dissipate in UV rays, you won’t have to add the chemical to your water as often as you would with chlorine.

In biguanide pools, a specialized oxidizer is needed to break down organic matter in the water. It’s important to use only biguanide-compatible chemicals and accessories to avoid damaging the pool or causing the water to cloud up.


  • Gentle on your eyes, skin, and hair
  • Does not dissipate in UV rays


  • Oxidizer and other chemicals needed to break down organic chemicals
  • Can cause your water to become foamy

I have a complete breakdown of biguanide vs. chlorine pools here.

Mineral Pools

A mineral pool is a great alternative to a traditional swimming pool. As mentioned, this is the best option if you want to opt for an alternative pool sanitizer. While not technically chemical-free, mineral pools require much less chlorine at only 0.5 ppm. Mineral pools work by taking the anti-bacterial properties of copper and silver, and use them to kill algae and sanitize the water. With a mineral pool, you don’t need to spend much money on sanitizing chemicals or dealing with the effects of high chlorine levels.


  • Natural method of sanitizing the pool water
  • Helps reduce the need for pool chemicals
  • Sanitizing system cartridges last months


  • Chlorine is still needed to supplement
  • Risks of metals oxidizing and staining your pool surfaces

Want to learn more? I go into a lot more detail in my comparisons of mineral pools to saltwater pools and vs. chlorine pools.

The Costs of Maintaining a Chemical-Free Pool

Chemical-free pools can cost quite a bit to set up, but since you’ll use fewer chemicals, they may cost less in the long run. A UV pool system costs between $300-$2,500, depending on the size and quality of the system. Ozone systems are a bit more expensive, costing around $1,000-$3,500. AOP pool systems are generally the most expensive, as they cost up to $5,000. You will still need to invest in basic pool equipment, such as a filtration system, skimmers, brushes, and vacuums.

You should still have some chlorine on hand for shocking your pool or adding small amounts.

Natural swimming pools can cost significantly more to install than standard pools as they require a lot of plants and unique systems to function. However, in the long run, you end up saving money with natural swimming pools.

Get My Free Pool Care Checklist

Download my free, printable pool maintenance checklist to help you accomplish regular pool care tasks for any type of swimming pool.

Something went wrong. Please check your entries and try again.

Final Thoughts

Chemical-free pools are a very interesting alternative that can be as safe as chlorine pools if adequately maintained. But, at the end of the day, chlorine pools are much better at killing bacteria and algae than natural pools. If you are not an experienced pool owner ready to put some elbow grease into cleaning, I don’t recommend a chemical-free pool.

Questions about chemical-free pools? Shoot me a message, and I’ll be happy to help.

Scroll to Top