Disinfection systems        

CONTENTS: Links to sections

Ioniser disinfection
Saltwater chlorination
UV water disinfection
Ozone disinfection
Hybrid systems
Products

Introduction

In the interests of company policy of only marketing products that have been fully tested by ourselves before inclusion into our catalogue, we generally describe all the pros and cons of all the available disinfection systems we sell and distribute.

Pool owners and operators can then make an informed decision based on environment, price, running costs, simplicity of installation and operation, and availability of parts and service.

Pool disinfection systems are designed to destroy bacteria, algae and animal pests such as lice, bugs, mites. Several methods are available. We describe here electro-mechanical equipment. For other chemical solutions please see our chemistry documentation.

What does chlorine not destroy?

According to many countries' bye laws for public pools, all pools disinfection systems must use chlorine as one of the agents. While proper chlorine levels (1 to 3 ppm) and pH balance (7.2 to 7.6) kill most bacteria (like E. coli) within minutes, several germs are chlorine-tolerant or entirely resistant, allowing them to survive for days or even weeks in swimming pools.

The most significant concern, Cryptosporidium (Crypto), this parasite is highly resistant to chlorine and causes severe watery diarrhea. It can survive for over 10 days in properly chlorinated water. 

Giardia is another parasite that causes diarrheal illness. It has a tough outer shell that allows it to survive for around 45 minutes to several days in chlorinated water. 

Pseudomonas aeruginosa is a bacterium commonly found in hot tubs and pools, responsible for ear infections and skin rashes (hot tub folliculitis). It can form biofilms that protect it from chlorine. 

Norovirus & Shigella, these viruses and bacteria can spread in pool water causing gastroenteritis, especially when fecal contamination occurs. 

What combination of methods works best?

The most effective swimming pool disinfection approach to destroy the widest spectrum of pathogens—including chlorine-resistant parasites—is a combination of AOP (Advanced Oxidation Process) or Ozone used as a secondary system alongside Chlorine as the primary residual sanitizer. UV works well as a complement to chlorine and some systems such as the Eaux Nanotech Series of UV units also come with an ozone generation attachment. These systems are not expensive. Using the right combination can significantly reduce the amount of chlorine needed which is an ideal solution for bathers who do not tolerate chlorine well. While chlorine is not a true allergen as it does not trigger an immune system response, it often acts as a strong chemical irritant that causes "irritant dermatitis," leading to red, itchy skin, rashes, or respiratory irritation like coughing and sneezing. People with sensitivities may mistake these irritant reactions for allergies. 

Ionizers

A natural and effective disinfection system for pools. Now the most cost effective, and easiest to install method of disinfecting a pool. Due to the increasing prices of chlorine and its availability, the problems of logistics for obtaining salt for salt water chlorinators, and the high cost of replacement cells, high quality ionizers are now available at highly competitive prices. The new generation of ClearBlue ionizers made in Canada provides an almost chlorine-free environment. They do not add any corrosive products to the pool that can damage metal fixtures and fittings, and unlike chlorine systems they do not affect the pH of the water. Ionizers are very easy to install and require no maintenance. ClearBlue electrodes are inexpensive and can be easily changed in one minute; they last for around 10 - 15 months under normal use. For very small pools up to about 30m3, an ionizer can be used as a stand-alone solution, but they are also an ideal complement to existing UV and salt water systems.

Advantages and User Benefits

• Low purchase price,compared to replacement chlorinator cell sof comparable performance
• Extremely low power consumption (about 7W)
• Crystal clear disinfected water
• Protection against 99.9% chlorine-resistant microorganisms and algae
• No chemicals added to the water
• Very easy DIY installation in 30 minutes
• Space-saving - no bypass or additional valves
• No health hazards whatsoever. Environmentally friendly
• Maintenance-free - 'set-and-forget'. No electrode cleaning required
• Easy 1-minute electrode replacement
• Inexpensive electrodes
• Electrode state is clearly visible at all times

For best results when using an ionizer you may wish to change the sand in your filter for glass filter media. ClearBlue is ideal for use with cartridge filters.

Downsides

• Like all 'chlorine-free' systems, the pool water needs the occasional addition of a small quantity of pool chlorine or a chlorine tablet.
• Occasional testing of the copper level (test strips supplied with ClearBlue ionisers)

How it works

A very low voltage current is supplied to an electrode. The electrode is a solid piece of metal, an alloy of silver, copper, and zinc. This self-sacrificial electrode releases ions of these natural elements into the water.

The disinfection properties of silver and copper have been known since ancient civilisations. They found that water in silver pots stayed purified, and algae didn’t grow in copper water containers. The hulls below the waterline of wooden sailing ships were clad with copper to resist the growth of algae and barnicles, hence the expression 'copper bottomed' for quality. NASA uses ionization for purifying the drinking water in space stations. There is also good reason that people are asked to throw coins in fountains and wells. Was it for good luck? Or was it the fact that the silver and copper in the coins actually purified and kept the water clean?

Mechanism of Action

In hospitals, copper-silver ionization is applied successfully for the deactivation of Legionella bacteria; wound dressings are impregnated with silver for its powerful disinfecting properties. Silver and most silver compounds have an oligodynamic effect and are toxic for bacteria, algae, and fungi in vitro. The antibacterial action of silver is dependent on the silver ion. The effectiveness of silver compounds as an antiseptic is based on the ability of the biologically active silver ion (Ag+) to irreversibly damage key enzyme systems in the cell membranes of pathogens.

The antibacterial action of silver has long been known to be enhanced by the presence of an electric field. Applying an electric current across silver electrodes enhances antibiotic action at the anode, due to the release of silver into the bacterial culture. The antibacterial action of electrodes with silver nanostructures is greatly improved in the presence of an electric field..

Read more about ClearBlue ionisers here.

Salt Water Chlorinated Pools