Chlorine Free Pools

Chlorine-free pools have become increasingly popular in Australia in recent years. This is because they claim to have a lot of benefits including reduced chemical usage, lower chlorine levels, healthier water, and fewer chemicals in your pool.  Is it all real, or is it just clever marketing?  This page discusses the good and bad aspects of chlorine free pools.

Chlorine-free pools sometimes referred to as “chemical-free”, “Low Chlorine”, “Mineral Pools” or “natural” pools, aim to provide a more eco-friendly and potentially less irritating alternative to traditionally chlorinated pools. These pools typically use alternative methods for water sanitation and maintenance. Here are some common approaches to creating chlorine-free pools. Remember almost all of these systems do use come chlorine.  In some Australian states, some chlorine use is required by law to keep the water safe.  

“Remember, most chlorine free or natural systems are simply low chlorine, not zero chlorine. Many use copper and silver or ozone to sanitize the pool water”

Chlorine-free pools – Your options

The video above shows how copper and silver work to significantly reduce the amount of chlorine and chemicals needed to maintain healthy pool water. This is because the copper and silver anodes dispense small amounts of copper and silver into the water.  These particles work to kill algae and bacteria. Because of this, little to no chlorine is needed to keep the water clear.  In Australia, there are several companies that make low (or no) chlorine systems. Some of these include:

Bromine Pools

Bromine is an alternative to chlorine for pool sanitation. Bromine pools offer a milder, less odorous water experience and are often preferred by individuals with chlorine allergies or sensitivities.  Bromine is suited to pools that run at higher temperatures (such as spas) and works well in these environments.  However, bromine pools can be more expensive to run than chlorine pools.  Because of this, very few larger outdoor inground pools run on bromine.  Most pool professionals advise only the use of bromine systems in hot tubs or heated pools.

Ozone and UV Systems

Some pools use ozone generators and UV (ultraviolet) light systems to help sanitize the water by killing bacteria and algae. These systems reduce the need for chlorine or other chemical sanitizers but may not entirely eliminate the need for some form of disinfection.  So, UV systems can be seen as a help (or a backup) to normal chlorine, not a replacement.  

Natural Swimming Pools

Natural swimming pools, or NSPs, rely on a combination of aquatic plants and beneficial bacteria to naturally filter and cleanse the water. These pools typically have a separate regeneration zone where plants and microbes break down contaminants. They do not use traditional chemicals or chlorination but in our experience are often a challenge to maintain in warmer climates.  Also, make sure you have ready access to a health care professional when you get a quote as they are far from cheap.  

Saltwater Pools

Saltwater pools use a salt chlorinator to generate chlorine from salt dissolved in the water. While they still contain and produce chlorine, the levels are lower and more stable than in traditionally chlorinated pools. Saltwater pools are often preferred for their easy maintenance and reduced chlorine odor and skin irritation.   They are also fairly cheap to run and install which is why they are popular.  Don’t forget that saltwater pool water is 10 times less salty than ocean seawater.  It is likely that you will not even notice the difference between salt and fresh water.

Salt water chlorinator
ionization pool system

Ionization Systems (Copper & Silver)

Ionization systems use suspended metallic ions, usually copper and silver, to inhibit the growth of algae and bacteria in the pool. While these systems reduce the need for chlorine, they may not entirely replace it in all cases.  For example, in warmer climates during summer these systems will sometimes struggle to keep the water clear during summer.  Because of this, you will need to add some extra chlorine throughout the year to keep the water clear and safe.  However, some systems will have an “oxidizer” built in which produces small amounts of chlorine to address this issue.  This is basically a mini saltwater system that runs alongside the copper and silver system.  These combined systems mean that you usually will not have to manually add extra chlorine.

Mineral Salts (magnesium pools)

These systems have become very popular in recent years as they are a mix between a traditional saltwater pool and a mineral pool.  The system itself is much like a normal salt pool in that the salt passes through an electrically charged element, just like a normal saltwater pool.  However, the salt that is added to the pool is heavy in minerals (hence the name) compared to normal white sea salt.  Also, the salt bags are usually 4-7 times the price of normal salt.  Some pool owners will alternate between mineral salt and normal salt to save money.  

Mineral salt

Chlorine free swimming pools – Do they reduce chemical usage?

One of the main selling points of Chlorine free pools is that your pool will require fewer chemicals to maintain the water balance. This is because of the reduced requirement of chlorine improves water balance.  However, most of these systems still use salt and produce a small amount of chlorine. Because a saltwater generator increases the pH of pool  water, the reduced levels mean that the water chemistry is more stable. Therefore, the water will need fewer chemicals to re-adjust the water.

On the other hand, most chlorine free pool systems still generate (or need)  low levels of chlorine to function safely.   Some manufacturers refer to the chlorine-producing part of the system as an oxidizer unit.  Don’t forget, this is just a fancy name for a small saltwater chlorinator. However, as mentioned earlier, the amount of chlorine needed is less than a normal pool.

How much do chlorine-free pools cost?

It’s essential to understand that achieving a completely chemical-free pool can be challenging, and even in chlorine-free pools, some form of sanitation or water treatment is usually necessary to maintain safe and clear water. Some of the alternative methods may require additional maintenance and costs. Also, water quality and sanitation effectiveness can vary depending on the specific method used.

Before choosing a chlorine-free pool system, consider the following factors.

Initial and ongoing costs: Some alternative systems may have higher upfront costs and maintenance expenses.

Local regulations and City Council rules: Check with local authorities to ensure that your chosen pool sanitation method complies with any regulations.

Personal preferences: Determine your priorities regarding water feel, odor, and environmental concerns.  Be careful to separate clever marketing from proper water science.

Maintenance requirements: Be prepared for any additional maintenance tasks or specialized equipment associated with your chosen method.

If you are considering a chlorine-free or alternative pool system, consult with a pool professional who has experience with these systems to determine the best approach for your specific needs and preferences.

Copper stain in pool

What are the pitfalls?

Generally, most people are happy with these systems and believe that they use less chemicals and like the way the water feels on their skin.  Others know that these systems often cost more to run and maintain but are OK with this to have better water.  However, from time to time, some pool owners can experience severe staining of the surface. This is because these systems work by producing a certain level of copper and silver ions floating (or suspended) in the water. Basically, these ions work to kill off any algae and bacteria in the water. However, if the water becomes out of balance then the copper and silver in the water can stain the surface.  Because the water carries higher levels of copper than a normal saltwater pool, this copper staining can be quite pronounced and hard to remove.

A final thought…

We don’t have an agenda and are not suggesting that one system is better than another.  However, many clients who upgrade to these systems usually do so because they find their normal pool water too harsh and uncomfortable.  Red eyes, heavy chlorine smells and other factors are usually the motivation to change.  While these systems can help with these things, they are not always the solution.  If your pool water feels uncomfortable to swim in it is usually a sign of unbalanced water, not chlorine.  So, before making a purchase of any kind, we challenge you to test your water more frequently.  If you feel that your pool water is hard or making you uncomfortable, do regular testing first.  You may be amazed at the difference balanced water can make to the way you feel in your own pool.