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Pool Sanitation Alternatives

Some Straight Talking on Pool Sanitation Systems

There is an ever-growing market in pool sanitation systems alternatives. As pool professionals, we are constantly asked which is the best.

The answer to this question has many variables, and muddying the water is a large amount of information available on the internet. A Google search will throw up a lot of information, the majority of which are advertisements for one system or another, which are coloured by the fact the information is provided by manufacturers or suppliers.

We have no reason to believe that the assertions made in these “advertisements” are not factual, nor claims made about their products cannot be substantiated. We merely observe that they project the systems in the best possible light and can choose to omit negative factors that do not support this view.

Truly informed research is sometimes hard to come by, so to help you separate the wheat from the chaff, we will endeavour to give you some pros and cons on all of the major sanitation systems available. We are going to avoid any manufacturers' or suppliers’ names.

Instead, we will concentrate on the base systems only as there are a plethora of hybrid combination systems available, but they are all based on the forms of sanitation as set out below.

It cannot be stressed enough that sanitation and filtration go hand in hand to produce clean, clear, safe and sparkling pool water. Please be aware that any sanitation system can only perform to its full potential with an installed efficiently operative filtration system correctly sized to the volume of water being filtered.

Chlorine / Bromine

Chlorine is still the most popular means of sanitising a swimming pool. It does an excellent job. It can be delivered to the pool in various ways, manually or by automated systems. We only recommend that fully automated delivery systems should be used to ensure that regular, reliable and adequate sanitation is supplied to the pool.

The forms of chlorine used in the swimming pool industry are:

  • Liquid Chlorine (Sodium Hypochlorite) - Not stabilised, 12% to 16% available chlorine
  • Calcium Hypochlorite -Not- Stabilised Granular or Tablet 65% to 75% available chlorine
  • Sodium Dichloroisocyanurate - Stabilised, Granular or Tablet 55% TO 65% available chlorine
  • TriChloroisocyanuric Acid - Stabilised, Granular or Tablet 90% to 95% available chlorine
  • Chlorine gas (rarely used) - Gas, 100% available chlorine
  • Bromine (Bromochloro-dimethylhydantoin)- Tablet, 99% available bromine.

Delivery systems vary; the common ones are as follows:*

  • Manual dosing
  • Floating dispensers
  • Erosion feeders
  • Chemical Dosing Pumps (Peristaltic), also used in conjunction with ORP Chemical controllers

*Fully automated delivery systems should be used.

Pros

  • Readily available.
  • Relatively cheap in its liquid form
  • Extremely effective sanitiser
  • Easy to apply and readily soluble product
  • It kills algae and bacteria such as listeria, E. coli and cryptosporidium
  • Can act as a short-term algaecide
  • Multiple delivery options
  • Low maintenance costs
  • Essential in the treatment of pathogens

Cons

  • Chlorine in some forms can be very caustic and in other forms be acidic
  • Its efficiency is reliant on pH control and temperature
  • Non-stabilised Chlorine is subject to depletion through the effects of UV (which requires the addition of a supplementary chemical to reduce this loss.)
  • In extreme cases, the formation of unwanted by-products such as chloramines and trihalomethanes
  • Difficult to estimate the amount of chlorine required equal to variable bather loads. Unless used in conjunction with an ORP/pH or PPM/pH control system
  • In some forms of dispensing, it may be hazardous to handle

*Be aware that there are far more effective and efficient ways to kill bacteria such as listeria, algae, E. coli and cryptosporidium as chlorine treatment for these bacteria are time in contact reliant

Salt Chlorinators

We hear a lot of people say we don’t have a chlorine pool; we have a salt pool. The only real salt pool is the ocean or rivers and pools fed by the ocean at a level of 3.5 to 4.5% salt. The main function of a salt chlorinator is to create chlorine from salt. This involves you adding a prescribed amount of salt to your pool, not chlorine, at a level of 0.35 to 0.6% salt. 

The salt acts as a precursor to the production of chlorine. Through electrolysis (via the connected cell), it converts the salt (Sodium Chloride NaCl) to Sodium Hypochlorite NaOCI or liquid chlorine, which when present in water, hydrolyzes rapidly to produce hypochlorous acid (HOCl). The hypochlorous acid will then dissociate into hypochlorite ions (OCl-) and hydrogen ions (H+). In short, it acts in exactly the same way as all other chlorine products.

Pros

  • Relatively modest setup cost
  • Pool salt relatively cheap in bulk form
  • Salt is not a consumable item and can only be lost through dilution
  • Users find the extra salinity in the water to be more comfortable on the eyes than straight liquid chlorine fed pools
  • Maintenance costs on par with chlorine
  • Wide range of chlorinator manufacturers to choose from
  • Non-hazardous form of chlorine delivery

Cons

  • Chlorine in this form can be very caustic
  • Its efficiency is reliant on pH control and temperature
  • It produces non-stabilised Chlorine, which is subject to depletion through the effects of UV (which requires the addition of a supplementary chemical to reduce this loss)
  • In extreme cases, the formation of unwanted by-products such as chloramines
  • The amount of chlorine production is reliant on the amperage and the run time of the unit
  • Difficult to estimate the amount of runtime to produce enough chlorine to match bather load, unless used in conjunction with an ORP/pH or PPM/pH control system
  • Regular adjustments to output levels are required
  • Since the amount of chlorine production per any given time is finite, supplemental addition of other forms of chlorine may be required for super chlorination

Mineral Salt Pools

The idea of mineral bathing is a century’s old phenomenon and conjures up the idea of a luxurious experience, rejuvenation, relaxation and enhanced water quality. Everybody has heard of the Dead Sea, its salt, mineral, cosmetic and healing properties. It has attracted visitors from around the world for thousands of years.

Mineral pool sanitation systems use varying mineral compositions (some of which are found in the Dead Sea) and have certain effects on the human body as well as the water quality itself. Generally speaking, a mineral pool is a pool that contains Minerals such as Sodium Chloride (salt), Magnesium Chloride, Potassium Chloride and Borates, naturally occurring minerals that enhance the bathing experience in addition to other essential water balancing chemicals.

After all the “feel good” palaver, in essence, these systems purely and simply work in the same way as a salt chlorine pool. The Chlorinator or Hydroxinator, as some manufactures call it, works in exactly the same way as a normal Salt Chlorinator. In fact, you can easily convert your salt chlorinated pool to a mineral-based pool without changing your chlorinator.

There is even a school of thought that the monthly addition of liquid magnesium to a normal salt chlorinated pool will produce the same benefits. The salt is a blend of minerals. Some even have sodium chloride NaCl in the blend to act as a precursor to chlorine production.

The blends that don’t have sodium chloride will have more than likely a healthy dose of Potassium Chloride KCl, which acts as the precursor. So yes, you end up with a chlorine pool again – created from a different base, but still chlorine (hypochlorite). Do you notice the recurring theme, that chlorine is an effective form of sanitation?

Pros

  • Soothes the skin, relieving those with sensitive skin to enjoy a swim
  • Detoxify the skin and body, by way of relaxing the nervous system
  • Softens and smooths the water, enhancing the bathing experience
  • Low to midrange running/maintenance costs
  • Non-hazardous form of chlorine delivery.
  • Ongoing maintenance costs low to medium
  • More often run at lower salinity levels.

Cons

  • Chlorine in this form can be very caustic
  • Its efficiency is reliant on pH control and temperature
  • More limited range of chlorinators to choose from
  • It produces non-stabilised Chlorine, which is subject to depletion through the effects of UV (which requires the addition of a supplementary chemical to reduce this loss.)
  • In extreme cases, the formation of unwanted by-products such as chloramines.
  • The amount of chlorine production is reliant on the amperage and the run time of the unit. 
  • Difficult to estimate the amount of runtime to produce enough chlorine to match the bather load. Unless used in conjunction with an ORP/pH or PPM/pH control system.
  • Regular adjustments to output levels are required.
  • Since the amount of chlorine production per any given time is finite, supplemental addition of other forms of chlorine may be required for super chlorination.
  • Be aware that the cost of the blended mineral salts normally will be 3 to 4 times the cost of just normal pool salt.

Ionised Pools

The benefits of copper and silver in the treatment of water dates back to ancient times, when it was found that water in a copper vessel remained algae free and water in a silver vessel remained pure. Well, that’s how the story goes. There have been attempts to replicate this phenomenon by adding silver to the filter medium to release silver ions into the water; a good way to go broke quickly. Then the introduction of an enclosed system was introduced to incorporate the properties of Copper and Silver.

These have been around since the ’80s and are generally sold as chlorine-free alternatives. These systems rely on a small electric current being passed between 2 heavy metals, like copper and silver rods. These rods erode over time, releasing copper / silver ions into the water.

The copper/silver ions in the water are not affected by temperature or sunlight. Copper/silver ions continue to work as a residual bactericide / algaecide even when the pool equipment is switched off. Copper silver systems do require either the addition of an oxidiser such as liquid chlorine or chlorine-free oxygen-based products or an incorporated oxidant production system (usually salt chlorination) to be used to oxidise suntan oils, perspiration, dust and body fats. The annual chemical running costs on these systems are midrange.

Although pool ioniser companies claim that their device allows for a chemical-free pool, there is no such thing as that. Second, copper and other heavy metal pool ionisers are slow-acting and require several hours to pass before the heavy metals may have any effect on bacteria and other pathogens.

Pros

  • It kills bacteria such as listeria, algae, E. coli and cryptosporidium*
  • It is not hazardous to the lungs and will not cause breathing problems or asthma attacks
  • Healthier for young children and older adults to swim in
  • There are no harmful gases being let off into the air
  • Easy on the eyes, ionised water will not cause eyes to get red, itchy, puffy or irritated.**
  • UV rays and evaporation does not have any effect on it

*Be aware that there are far more effective and efficient ways to kill bacteria such as listeria, algae, e-coli and cryptosporidium as this treatment for these bacteria are time in contact reliant

** “Easy on the eyes” is more a product of pH control rather than the use of heavy metals.

Cons

  • Visible staining. Pool ionisation most often leads to staining on a pool's interior surface or liner.
  • Uncontrolled copper levels can also turn blond hair green in conjunction with relatively low chlorine levels.
  • Ionisers don't neutralise organic materials, such as body oils, natural suntan lotions, pollen, dirt or urine. As a result, the level of total dissolved solids, called TDS, must be tested frequently.
  • Ionisation isn't a solo act. Pool ionisers must be used in conjunction with chemical sanitisers. Even though ionisation decreases the amount of chemicals you need to clean a pool, some chemicals are still necessary.
  • Due to most health departments’ recommended chemical criteria regarding chlorine residuals, it is not a preferred option for commercial installations.
  • Not operator friendly; needs constant monitoring.

Ozone Generation

Ozone is a highly effective oxidiser. It is an unstable molecule, O3, and tries to stabilise itself by attaching to organic debris and oxidising it during this process. An oxidiser such as ozone also reacts with chloramines in pool water (chlorine that has combined with organic matter) to oxidise the chloramines.

Ozone, in fact, is a great swimming pool oxidiser and sanitiser and is a safe alternative to chlorine. It destroys contaminants and kills bacteria simultaneously. They are specifically designed to assure that no ozone ever reaches your swimming pool or the swimmers in it. While it is available for swimming pools, we tend to find it more economically viable for smaller bodies of water such as spas.

Ozone is produced for swimming pool water by these two methods. In the UV method, air is passed over a UV bulb and the radiation creates nascent oxygen. For ozone, or the corona discharge method, a pool ozonator creates a small lightning storm in an air-filled chamber.

Pros

  • Ozone prevents the formation of chlorine or bromine-containing by-products, like chloramines and trihalomethanes
  • Ozone disinfection qualities are not dependent on pH, nor does the addition of ozone affect the pH of water.*
  • Ozone is over 3000 times faster to purify water than chlorine or ionised methods
  • Ozone also eliminates pool odours common to traditional pools
  • Removes metal like iron and manganese
  • Relatively low running costs.
  • Removes Bacteria, viruses and Hydrogen sulphides.

*Though ozone is not pH dependent, pH control is recommended, so water remains “easy on the eyes”.

Cons

  • Unable to easily measure Ozone residual
  • Ozone highly toxic
  • High initial cost
  • Difficult to determine the amount of Ozone generation required.
  • Requires chlorine residual produced by some integrated sanitation device.
  • Not in common use in domestic or commercial pool market
  • Makes more economical sense for smaller bodies of water

Natural Pools
Some Honourable Mentions

Natural Pools, relying on botanical organic filtration chemical-free sanitation.

Living Pools, an underground biological filter and a specially developed phosphorus filter provide biological and physiological purification of the water.

Without going into great detail about these types of pools as they are not a prevalent form factor compared to the above forms of sanitation. So the Pros and Cons will be brief.

Pros

  • Truly chemical-free swimming
  • Low running costs

Cons

  • Very large footprint if you are, say, contemplating a standard 50,000lt pool
  • Very high setup cost

This blog attempts to give you some broad strokes to enable you to make an informed decision. We didn’t want to get bogged down with different manufacturers or types of hybrid systems that are available. Just be aware that they all rely on the basic principles mentioned above.

When making your decision, it is always best to contact a truly independent professional like Billabong Pool Service & Supply to analyse your pool sanitation needs and provide you with the most cost-effective and efficient solution. So, drop in and see us at one of our three locations Noosa, Maroochydore and Caloundra, QLD.

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