Water filters for your home

Several water filters currently on the market will effectively improve the taste and odour of water.

Filtration can remove tastes and odours whether they are naturally occurring or caused by a disinfection process.

Only a reverse osmosis water filtration system will effectively remove harmful bacteria.

The simplest way to remove harmful bacteria is to disinfect the water by chlorination or by ultraviolet radiation.

As some water filters remove biocides (substances that can control the growth of harmful organisms, such as chlorine), it is possible that bacteria will re-grow unless the filtered water is stored in a sterile container in a cool, dark place.

Some water filters may also allow bacteria to multiply to great levels on the filter pads if they are not maintained regularly.

In most circumstances domestic household water filters or ultra violet treatment systems will not make water safe in relation to amoeba unless you also disinfect with chlorine. Read more about amoebic meningitis.

Some water filters will soften hard water. Hard water contains calcium and magnesium salts which results in:

• the need to use more soap
• a build up of scale on plumbing fixtures
• a metallic taste to water.

Water filters that are currently available to consumers include:

• polypropylene and ceramic
• activated carbon
• reverse osmosis and distiller.

The most sophisticated systems are reverse osmosis and distiller filters.

Polypropylene and ceramic filters

Polypropylene and ceramic filters function by removing particles from the water. Fibres are packed tightly together to form a fine mesh screen that physically traps and removes foreign particles from the water.

However, as these filters become clogged it is necessary to dispose of the filter or cartridge and replace it with a new one. Some filters may also soften hard water.

Activated carbon filters

Activated carbon filters are most effective in removing chemicals such as iron, manganese, chlorine and hydrogen sulphide along with objectionable tastes and odours.

Some may also contain ion exchange resins that can soften hard water.

Polypropylene, ceramic or activated carbon filters should not be relied upon to disinfect water.

Reverse osmosis filters and distillers

Reverse osmosis filters and distillers are the most sophisticated systems. They are capable of removing bacteria and most residual chemicals, including minerals from a water source.

However, reverse osmosis and distillers are not effective in removing hydrogen sulphide (a gas with an unpleasant ‘rotten eggs’ smell) in acidic waters.

If you are considering drinking mainly from distilled water or similar demineralised sources, please discuss this with your family doctor to ascertain if this is the right option for you. In general, avoid using distilled water or demineralised water when reconstituting infant formula.

The cost of water filters varies considerably.

Some water filters are simple two-tiered jugs while others connect directly to the kitchen tap and are located either on or under the bench.

Reverse osmosis filters are the most expensive to purchase, install and operate.

For discoloured water with fine particles of grit and other foreign material, a polypropylene or ceramic filter will effectively remove the sediment. It will not remove bacteria.

To remove naturally occurring or disinfection tastes and odours from water an activated carbon filter is more appropriate. It will not remove bacteria.

To remove chemicals and bacteria, a reverse osmosis or distiller system would be required.

In most circumstances domestic household water filters or ultra violet treatment systems will not make water safe in relation to amoeba unless you also disinfect with chlorine. Read more about amoebic meningitis.

It is not necessary to filter water from scheme drinking water supplies in Western Australia unless you live in an area where you may need to soften hard water.

The Department of Health requires scheme drinking water suppliers in Western Australia to supply drinking water that is safe and complies with the Australian Drinking Water Guidelines (external site).

Routine sampling and reporting to the Department of Health ensures that drinking water provided to consumers from drinking water suppliers in Western Australia is of the highest microbiological and chemical quality.

From June 1993 all fixtures and appliances must carry either a standard WaterMark or a Plumbing Safety Type Test Mark.

Look for these marks to make sure you buy a water filter that meets the standards.

This mark assures the buyer that the product has been tested by an independent laboratory and will function properly.

If you are renting out a residential property with domestic water filters, on either a short term or long term basis, it is best to ensure that the tenancy agreement or lease clarifies which party (the agent or the tenant) is responsible for maintaining the water filter and periodic replacement of any filter cartridge during the tenancy.

Checklist for buying a water filter

• Work out the volume of water that needs to be filtered.
• Decide on the type of filter that you need based on what you want to remove, for example odour, grit, chemicals.
• Buy a filter that has the standard WaterMark or Plumbing Safety Type Test mark.

Checklist for using a water filter

• Always follow the manufacturer’s instructions, including periodic replacement of any filter cartridges.
• Ensure the filtered water is disinfected prior to consumption.
• Store filtered water in a sterile container in a cool, dark place to prevent contamination.