For generations, chlorine has ruled the swimming pool industry. But what happens when the King is put to the test — and the results don’t live up to his reputation?
Most Australian pool owners have been led to believe that chlorine is simply the best way to keep swimming pool water safe.
It’s what pool shops recommend. It’s what most pool professionals have traditionally used. And it’s the chemical around which much of the swimming pool industry has been built.
But there’s a question that very few people ever ask:
Is chlorine really the best available swimming pool sanitiser, or has it become a protected species because that’s the way the industry has always done things?
At Enviroswim, we’ve been asking that question for more than 25 years.
And we have some rather interesting scientific evidence to share.
When the King was put to the test
Back in 2001, independent microbiologist Dr Paul Wright PhD, working at Tweed Laboratory Centre, a commercial unit of Tweed Shire Council, conducted laboratory tests comparing chlorine alone with water treated using copper and silver ionisation alongside chlorine.
The tests examined how quickly the treatments could destroy a potentially harmful bacterium called Pseudomonas aeruginosa, which is associated with swimming pool and spa infections.
The NSW Health test requirement was straightforward:
Destroy at least 99.99% of the bacteria within 30 seconds.
No complicated chemistry lesson is necessary. The objective was to see how effectively the different treatments could eliminate bacteria in a specified time.
Chlorine was tested at three different concentrations.
Not one of the three chlorine-only treatments achieved the required result within 30 seconds.
However, the copper/silver-treated water combined with chlorine achieved the requirement at two of the three concentrations tested.
Dr Wright’s report specifically confirmed that none of the three chlorine-only levels met the 30-second requirement.
Even more remarkably, in a separate experiment, chlorine alone first recorded a passing result at the 15-minute sampling point.
That’s a considerable difference from the required 30 seconds. The report does not establish the exact moment chlorine reached the target between samples, but it certainly didn’t demonstrate the required performance at 30 seconds.
Does this mean chlorine cannot disinfect water? Of course not. Chlorine has genuine disinfecting properties.
But it does mean that under those independently documented test conditions, the industry’s long-established favourite failed to achieve the specified rapid-disinfection target.
And that should concern anyone who believes swimming pool safety ought to be determined by science rather than reputation.
Three years later, Enviroswim returned to the laboratory
In 2004, Dr Wright conducted further testing at the same laboratory, this time examining an operating Enviroswim treatment system in spa water.
The results were exceptional.
In two separate trials, the Enviroswim system achieved bacterial reductions of more than 99.99% within just 30 seconds, exceeding the NSW Health performance target.
After only two minutes, the tests recorded reductions approaching 99.9999% or greater.
Significantly, the laboratory reported that the chlorine level in both spas was below 0.01 mg/L before each experiment.
In other words, these impressive results were achieved without a measurable chlorine residual above that reported level at the start of testing.
These were separate trials from the 2001 chlorine comparison, using different experimental arrangements, rather than a direct head-to-head test of the two systems. Nevertheless, both reports used the same microbiologist, laboratory, target bacterium and 30-second performance criterion.
The 2004 system was an earlier Enviroswim configuration, not a documented test of every component of today’s ES3 V3.
For Enviroswim, these findings provided an important scientific foundation for further development of our technology.
But they also raised an uncomfortable question: if alternative technology could demonstrate such rapid bacterial reduction, why was chlorine still treated as the unquestioned benchmark?
We asked Australia’s regulator to show us the evidence
In 2014, Enviroswim went a step further.
We lodged a formal Freedom of Information request with the Australian Pesticides and Veterinary Medicines Authority (APVMA), the Australian Government regulator responsible for registering swimming pool sanitisers.
We requested scientific evidence showing that three specified registered pool sanitiser products, including two chlorine products, met the APVMA’s nominated efficacy guidelines.
After searching the relevant records, the regulator issued a written decision.
Its conclusion was extraordinary:
“The documents sought do not exist.”
That statement came directly from the regulator’s own Freedom of Information decision.
To be precise, the decision concerned the particular scientific documents requested. The APVMA explained that the cited guidelines applied to applications or reviews from July 2014, and that no qualifying new applications or reviews had occurred for those products.
It did not establish that chlorine has no scientific evidence supporting its disinfecting properties.
But it did establish that the APVMA could not produce the particular documentation Enviroswim requested.
So the question remains: if established sanitisers are treated as the benchmark, shouldn’t the supporting science be available for everyone to examine?
Especially the people trusting those products to keep their families safe.
Has chlorine become a protected species?
Imagine a competition where the reigning champion is allowed to rely on a long-standing reputation, while every newcomer is required to produce detailed scientific evidence before entering.
Would you call that a level playing field?
This is precisely the concern Enviroswim has raised with Australia’s pool sanitiser regulatory system.
The APVMA has established requirements for new sanitisers to demonstrate that they work.
At the same time, certain established home-pool chlorine products can be registered through a regulatory pathway that relies on compliance with an existing product standard rather than a separate efficacy assessment of each individual product.
There is a legal framework behind that arrangement. But the scientific foundation of the standard should be just as open to examination as the evidence demanded of competing technologies.
In our view, chlorine has effectively become a protected species within the pool industry — not because its benefits are imaginary, but because tradition and established regulatory pathways can favour the incumbent.
That is not an allegation of an unlawful conspiracy. It is a serious question about whether innovation and established technologies are being subjected to equally transparent scientific scrutiny.
And after more than two decades developing an Australian alternative, we believe pool owners deserve an answer.
The good news: pool owners have a choice
Swimming pool technology has moved forward considerably.
Enviroswim’s modern ES3 V3 freshwater sanitising system combines three complementary processes:
- Copper and silver ionisation to help control microorganisms and algae.
- Electronic oxidation to treat contaminants in the water.
- Ultrasonics as part of the integrated treatment process.
The system is designed to maintain swimming pool water without relying on routine chlorine dosing in suitable residential applications.
And here’s something many pool owners don’t realise: a saltwater pool is usually still a chlorine pool. Its salt chlorinator simply produces the chlorine on site. Many so-called mineral pools also continue to rely on chlorine.
Enviroswim offers a fundamentally different approach.
Reducing reliance on chlorine also reduces the source of chlorine-derived disinfection by-products, while removing much of the chemical handling traditionally associated with owning a pool.
For families looking for a more enjoyable freshwater swimming experience, that is worth investigating.
It’s time the King earned his crown
We are not asking anyone to take Enviroswim’s word for it.
We have made our scientific evidence and regulatory submissions available for people to read and question.
We are not suggesting that chlorine never works, nor that it should automatically be prohibited.
Our position is much simpler:
Every swimming pool sanitiser — chlorine included — should be judged by the same transparent, independently verifiable scientific principles.
After all, when it comes to the safety of your family, tradition is no substitute for evidence.
Chlorine has enjoyed the crown for generations.
But perhaps it’s time pool owners started asking whether that crown has been earned through demonstrable performance — or simply inherited because nobody was supposed to challenge the King.
Chlorine may have ruled the swimming pool industry for decades. But is it truly the King — or a pretender to the throne whose crown has been protected for far too long?
Don’t just take our word for it. Examine the evidence.
We believe consumers should have access to the original documents, not merely manufacturers’ advertising claims.
- Read the 2001 Tweed Laboratory comparison and NSW Health criteria
- Read the 2004 Tweed Laboratory Enviroswim efficacy report
- Read the APVMA’s 2014 Freedom of Information decision
- Explore Enviroswim’s testing and accreditations
- Read our submissions on Australian swimming pool standards
Considering a new pool or looking for a better way to maintain your existing pool?
Discover the Australian-developed Enviroswim freshwater sanitising system at www.enviroswim.com.