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Chlorine is the most common form of pool water sanitation used around the world. It is an effective sanitiser when used correctly, however it is extremely volatile, making it hard to maintain a continuous safe residual level in a swimming pool. The number of serious health issues associated with chlorination are growing at an alarming rate, prompting enquiries for safer alternatives. There is little good research with regards to the efficacy of chlorine at levels that are safe to swim in.

Chlorine requires constant attention and dosing to maintain safe levels, is extremely corrosive to pool equipment, stone, cement, surrounding plants, coping and bathing suits, and requires regular physical handling and  transportation of the concentrated chemicals. Constant ongoing chemical costs including chlorine, stabilizer, acid, buffer, algaecides, floc, shock more……Industry favoured due to constant revenue stream.

Whilst growing attention is focusing on the health concerns surrounding the use of chlorination for water treatment, another chemical associated with its use is also causing concern. Cyanuric acid (better known as stabilizer) is used as a sun screen or UV protector to hold chlorine in the water for longer periods by reducing the sunlight’s degradation. Cyanuric acid (CAS No 108-80-5) is a structural analogue of melamine. It may be found as an impurity of melamine. Unlike most pool chemicals that will degrade or can be adjusted using other chemicals – Cyanuric Acid is a forever chemical. Reduction can only be achieved by dumping pool water with the Cyanuric Acid remaining in the environment forever.

Salt water chlorination is the most commonly used pool sanitising system in New Zealand and Australia. It works by adding salt to the pool water which is then converted to chlorine using an electrolysis process as water passes through the treatment cell. The most commonly used salt is sodium chloride. More recently there has been a trend to substitute some of the sodium chloride with magnesium & potassium chloride but the end result is the same: chlorides are converted to chlorine using electrolysis.

Clever marketing campaigns have resulted in a lot of users believing that a salt pool does not produce chlorine. The fact is, the sanitiser is 100% chlorine. Recently the word ‘salt’ has been substituted with “mineral” in marketing campaigns, but the methodology has not changed; they are still 100% chlorine. Salt pools typically require 3000 – 6000 parts per million of salt (ppm). Recently there have been a few systems emerging on the market that operate a little lower at around 2500 ppm.

Pros:

+ Reduced cost and handling associated with conventional chlorine treatment

+ Provides automated chlorination while pool equipment is running

Cons:

– Requires ongoing expensive chemical back up, including stabiliser, algaecides, flocculants and shock treatments

– Exposure to high chlorine levels and associated health risks as detailed in the ‘Chlorine’ section above

– Can prove difficult to maintain correct residual chlorine levels in conditions of high heat, sunlight and bather load – chlorine and heat do not go well  together

– Salt chlorination only works when the pump is running, resulting in lengthy run times and high energy costs. Water is high in total dissolved solids (TDS), corrosive, brackish and cannot be recycled without dilution

– Salt water can damage rock features, pool surrounds, equipment and gardens

Ozone is an effective powerful oxidiser that has a very short life. The ozonator
produces ozone gas that is injected into the pool circulation system to aid the
residual sanitiser. Ozone is becoming a popular back up for chlorine systems and salt water chlorinators.

Pros:

Powerful oxidiser.

Cons:

Expensive to purchase and maintain, provides point of contact treatment only and has no residual protection for the bather, Ozone gas is very toxic, the ozone generator must be installed in a way that it will prevent the ozone gas getting into the main pool water. Most Domestic Ozone installations do not have a degassing chamber fitted. Ozone requires an additional residual sanitiser most commonly chlorine and its associated chemicals. Only works when pump is running. An expensive add on that should not be required if the residual sanitiser is maintained correctly. There is no simple test that the ozone generator is in fact working and frequent expensive replacement of corona discharge is required.

Ozone + Salt
Uses a combination of salt water chlorination and ozone injection. The residual sanitiser protecting bathers is 100% chlorine similar to other salt chlorinators. Like all salt systems, ozone/salt uses high salt levels resulting in brackish water. The ozone component is a secondary sanitiser which is mainly used in public pools to help reduce chloramines that are more commonly an issue in commercial pools with high bather loads.

Pros:

The addition of ozone treatment in chlorinated treated pools has been shown to reduce harmful chloramines and reduce chlorine consumption. This is certainly a benefit when used in public pools where high bather loads create increased chlorine demand which can result in high chloramine levels if the chlorine level struggles to maintain a recommended level commonly around 2 ppm – 4 ppm chlorine residual. When you detect the smell of chlorine in an indoor public pool it is a sign that there is not enough chlorine in the water. The smell is chloramines, not chlorine. Chloramines are less of an issue in residential pools.

Cons:

The claim that there can be a safe reduction in chlorine residual levels and still safely sanitise the water need some scientific back up given that the water only gets treated one to two times a day with ozone as it passes through the ozonator which is a point of a contact sanitiser only, meaning it offers no residual protection for bathers if bacteria or parasites are in the main body of pool water. Safe residual sanitisers need to demonstrate bacteria kill times in a matter of seconds to help prevent the proliferation of bugs and protect bather contamination & infection. Getting a dose of ozone once or twice a day as the water passes through the ozone cell won’t do that. Running low chlorine levels using this methodology will offer lower reserves to maintain sanitiser kill rates and very poor algae control in outdoor pools.
The addition of ozone as a secondary sanitiser should reduce the quantity of
chlorine required to maintain safe sanitiser level but this is very different to lowering the active chlorine residual level.

Ionisation:
Copper and silver are nature’s mineral sanitisers and have been used for thousands of years to sanitise water, treat burns, and for many other uses. You will probably have used silver based treatments for conjunctivitis. More recently NASA developed ionisation for sanitation use on the Apollo missions.

Pros:

Copper and Silver are unaffected by heat and UV which makes it easy to maintain a residual level in pool water. The copper and silver ions continue to work as an algaecide and biocide in the pool water, even when the equipment is turned off.

Cons:

Ionisers do not oxidise the organic compounds in the pool such as oils, dust and urine. They require a residual oxidiser (usually chlorine) to be added to the pool. Under certain conditions Ionisers can stain some types of pool surfaces. There are many ioniser/oxidiser brands on the market. Enviroswim is often mistakenly regarded as a similar product however it is not. Enviroswim’s patented technology is unique, uses a different methodology and is backed up by independent testing. For example, if we compare Enviroswim with other ionisers using oxidiser add-ons, the Enviroswim Oxidiser is a powerful 225 watts compared others that quote a maximum of 9 watts. 9 Watts at the oxidiser cell will have little to no affect as an oxidising agent in swimming pool water and will certainly require the frequent
addition of chemical oxidisers such as chlorine to ensure safe water quality and good clarity. Our tip: a little time spent researching products and asking suppliers for third party independent evidence & assurances that their product will maintain your pool in a safe and reliable manner, is time well spent to help avoid disappointment and exposure to life threatening bacteria later on. Confused? Contact us and we will explain what to look and ask for.

Ozone provides point of contact treatment (in line only) and has no residual
disinfectant protection for the general bathing area. UV is classed as a secondary sanitiser used to back up the primary residual sanitiser. Hydrogen Peroxide is a powerful oxidiser (depending on concentration) but has very limited disinfectant properties at safe human exposure levels in pools and spas. Hydrogen peroxide has been used as the oxidiser component in pools & spas in combination with other disinfectants like Polyhexanide. It is used as a hard surface disinfectant and has been granted registration for this purpose by the US EPA. When used as a hard surface disinfectant, hydrogen peroxide is normally used at around 3% (30,000 ppm)
When used in recreational water, hydrogen peroxide is used as an oxidiser at levels of 100 to 150 ppm. At these low concentrations it is easy to see why hydrogen peroxide is not an effective disinfectant. UV-peroxide systems do not provide a persistent disinfectant in the bulk of the water in the facility. Further, hydrogen peroxide is not registered by the US EPA for use as a disinfectant in recreational water. The methodology of combining Ozone and Hydrogen Peroxide for swimming pool sanitation is considered unsatisfactory by most Australian State Health Departments. Its sale as a pool sanitiser is banned in the USA, Canada & most of Europe.

Pros:

It is impossible to find any pros on these systems, as the methodology to date is scientifically proven to be an ineffective pool sanitising option by most health departments worldwide.

Cons:

Products to date have not been laboratory tested to meet the APVMA efficacy Test criteria as a satisfactory pool & spa sanitiser for use in Australia, details here. It is unlikely that hydrogen peroxide even when combined with silver could meet the required residual disinfectant criteria to ensure safe pool water and protect bathers from serious illness or worse. All previous scientific studies using ozone and hydrogen peroxide have proven hydrogen peroxide as a residual pool sanitiser to be ineffective. Ozone whilst having a good disinfectant efficacy only disinfects at point of contact and is very toxic, therefore no ozone residual must enter the pool bather area. This then leaves hydrogen peroxide as the only residual disinfectant protecting bathers. Certainly unsafe, unproven & not recommended. Other issues associated with these systems are the high ongoing running costs of purchasing, dosing and handling hydrogen peroxide in large volumes. Hydrogen Peroxide can also cause respiratory issues when used at concentrations high enough to provide a small amount of disinfectant in water.

Note:

We welcome innovative competition but we have a problem with ozone/hydrogen peroxide systems, a claimed “new invention” that in our opinion is being deceptively advertised as an “approved” new product without first completing the APVMA approval laboratory requirements to ensure the safe introduction of a “new” sanitising system. The available scientific data from Health Departments, CDC, EPA highlights the methodology as unsatisfactory for safe pool disinfection.. We are currently in communication with the APVMA and the Gold Coast City Council who
have denied any approval of the system other than allowing a trial based on
assurances from the manufacturer! What assurances do they have to refute the current scientific data? A lot of advertising material in our opinion is grossly deceiving and misleading for the uninitiated. We urge you to research all products before making any decision to avoid costly disappointment and risk to bathers. Here are a few links on Ozone + Hydrogen Peroxide, read pages 52/53 on this link , Vic Health Department link , NSW Health pg 26 link.

Update:

We recently requested from the APVMA under their ”Freedom of Information” process, the scientific data they are relying upon to support their approval of Hydrogen Peroxide & Chlorine as suitable pool & spa sanitisers that meet their recently published efficacy guidelines for new sanitisers. Their reply “The information does not exist”. Read the decision report at this APVMA link dated 29th Aug 2014. The APVMA have also stated that they take no responsibility for public health & safety or approval of the use of their registered pool sanitisers, that responsibility falls upon individual State Health Authorities. Given the recent response we believe the APVMA should now review the suitability and efficacy of all chlorine & hydrogen peroxide based registered chemical pool sanitisers.
In the case of hydrogen peroxide the APVMA has confirmed they have no scientific data to suggest it is a satisfactory pool sanitiser that meets their pool sanitiser efficacy requirements, in contrast there is an overwhelming amount of data to suggest it does not.
Enviroswim and a few other systems are available that completely eliminate the need for the public to purchase, handle & store dangerous pool sanitising chemicals in residential and commercial properties.

Promoted as a chlorine free system, baquacil has been used for many years in small residential pools. It is not a very effective sanitiser and is not recommended for use in commercial pools or large residential pools. Its popularity has waned over the years due to the operating costs.

Pros:

Chlorine Free.

Cons:

Polyhexanide is currently under review by the Australian Pesticides & Veterinary Medical Authority (APVMA) due to carcinogenic (cancer causing) concerns with the chemical. Polyhexanide can also cause anaphylactic shock, its use is banned in many parts of the world for this reason. It is also known to cause irritation & inflame allergies in pool water. see this link. A quick Google search on “baquacil problems” will highlight the issues to anyone considering using this method for sanitising swimming pools & spas. Polyhexanide also requires Hydrogen Peroxide to be added to the pool at regular intervals as an active oxidiser, therefore adding to the ongoing
running costs and handling of dangerous chemicals. Chlorine is not  compatible and must not be used in with this system.

Natural Swimming Pools

A Natural pool is a system where the water is treated biologically, without the use of chlorine and chemicals. The water passes through the sand filter beds, where aerobic and anaerobic bacteria live ready to attack single cell algae. The regeneration zone has plants that feed on the nutrients, starving the food source that algae live off.

We are passionate about minimising or eliminating harmful chemicals in swimming pools, however, there has to be a common-sense approach to this when it comes to bather safety. We understand these pools originated in northern Europe where cooler climates and water temperatures showed some success in using the methodology. In New Zealand, we’re receiving a growing number of enquiries from natural pool owners & builders to see if they can add an Enviroswim system to the natural system in an effort to eliminate the unsightly algae growth and improve water quality.
The choice is clear to us; you can choose to build a pond and accept the fact that the pool will have algae, slimy surfaces and no proven sanitising properties or you can build a controlled, clean environment swimming pool designed to provide a safe clean environment to swim in, using minimal chemicals. There seems to be little, if any mention of the sanitising properties of the water using a natural pool system, maybe it's because there are none!

Enviroswim ES3 System Unique Patented Electronic Sanitiser

Enviroswim ES3 patented system provides sparkling fresh water using natural minerals, ultrasonics and electronic oxidising. Enviroswim water is low in total dissolved solids (TDS) creating a healthy freshwater environment. Water can be discharged anywhere. This is achieved by eliminating most of the regular dissolved chemical additives associated with conventional systems.

Pros:

Eliminates the need to purchase, handle or add liquid chlorine, granular chlorine, hydrogen peroxide, stabiliser (cyanuric acid see chlorine section above), non-chlorine oxidiser, algaecides & flocculant. Reduces energy costs, chemical costs, chemical handling, exposure to toxic/carcinogenic by-products associated with chlorine and cyanuric acid. Provides a genuine return on investment through low running costs together with health and environmental benefits. Pool water/backwash can be used undiluted on gardens and does not attack rock features and copings.
With Government supported development, in 2009 Enviroswim met certification as a standalone sanitiser, providing world leading independent assurances for consumers.

Cons:

Initial cost is higher than some other methods, however unlike our chemical hungry competitors, Enviroswim provides a true return on investment and will provide a pay back on the extra upfront cost in a very short time. Unfortunately, the pool industry is still dominated by traditional chemical approaches – especially chlorine. Pool shops and many maintenance operators are driven by the high chemical margins making enviroswim an unattractive proposition for them.

Summary:

There are many products on the market making claims that are unsubstantiated. Most are designed to feed the recurring chemical revenue stream that supports the pool industry.
Enviroswim is different; we have little to offer the industry in terms of ongoing chemical sales & revenue. A consequence of this is, many pool shops, pool techs and advisory blogs will attempt to talk uninitiated pool owners out of using the Enviroswim system with claims that it is “not approved” “doesn’t work” “not safe”.
Nothing could be further from the truth. The facts don’t lie. Enviroswim is one of a few products in the world that has been rigorously tested by independent certifiers and a government laboratory proving it to be far more effective than chlorine for controlling common pool bacteria. Enviroswim has years of trouble-free history working in commercial pools that are tested monthly for microbiological contamination.
We will happily defend and back up the information & comparisons listed on this page. As always, we urge pool owners to do their research in order to make an informed decision.

Ultimately it is your money and your choice, don’t be talked into a system that benefits the reseller more than you the purchaser.

Read more about the average cost of running a swimming pool.