Wellington Water Filters
and
Kapiti Pure Water

39 Amohia Street
Paraparaumu
New Zealand

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Taste & Odour / Chemicals

The basis of all purifiers is a substance called 'Activated Carbon'. Activated Carbon is initially derived from either coconut fibre or coal which is treated (or 'Activated') by being subjected to extreme temperatures and steam in the absence of oxygen. This process produces an extremely porous material on which organic molecules are adsorbed. The surface area of Activated Carbon is very high, with one kilogram of Activated Carbon having a surface area of around 112 hectares. Activated Carbon can either be in a loose 'Granular' form or a compressed tube commonly called a 'Carbon Block'.

If your main concern is to improve the taste of the water and the removal of chemicals, either a GAC (Granulated Activated Carbon) or a Carbon Block cartridge will do the trick nicely. The quality, density and source of the carbon used in different cartridges varies enormously and effects the final performance. The cheaper cartridges will improve the flavour of the water, but the better cartridges will remove a wider range of chemicals as well as THM's, and aluminium sulphate.

The hygienic life of carbon cartridges varies from 6 months to 2 years depending on the manufacturing process and the source of the Activated Carbon. Loose granulated carbon is generally less hygienic than a tightly bonded block cartridge. Some cartridges have silver bonded with the carbon to increase the hygienic life, as silver is a natural media which restricts many bacteria from breeding.

Heavy Metals

Most Water Purifiers use Activated Carbon as the principle purification media, but this will not remove the full range of potential 'Heavy Metals' from water. Most metals occur due to corrosion of copper pipe fittings by acidic or 'aggressive' water. Other metals can be leached or washed into water supplies from industrial activities, although this would be rare in New Zealand.

To remove metals such as lead, nickel, cadmium, mercury, arsenic, etc, you will need a cartridge which includes a material called KDF. KDF also increases the hygienic life of a carbon cartridge by up to three years, because it helps to prevent the growth of bacteria within the cartridge. KDF should not be used for untreated bore or roof water supplies. It should also be noted that because the KDF media exchanges chlorine & metal ions for zinc ions, there can sometimes be a very slight bitter taste caused by the output of the zinc. A standard Carbon Block cartridge therefore tends to produce a slightly sweeter taste.

Giardia & Cryptosporidium

If you want to be sure you do not become infected with Giardia or Cryptosporidium cysts you will need to choose a cartridge with a 1 micron or less filter. The cysts may pass through a filter any larger than this and are not killed by Chlorination or most UV light treatment systems. Both these protozoa are present in the Wellington, Kapiti, & Otaki source water supplies. Although the Council water treatment process on the whole is fairly effective at removing them, there is still a risk of infection and the occurrence of people being infected with these protozoa is now quite common.

We must also remember times such as when the Wainuiomata treatment plant was temporarily shut down in late 1998 because of uncontrollably high Giardia counts in the water, and the contamination of the Masterton water supply with Cryptosporidium a few years ago. We believe we should all take the precaution by filtering these from our private water supplies.

Minerals

Natural minerals in the water supply will not be removed by either carbon or KDF Purifiers.
This includes Fluoride which is a mineral. If you want to remove the added 'Sodium Fluoride'
you can either use a cartridge with 'Actival', ( a fluoride specific resin ), or Reverse Osmosis. Please ask us for further details on the options available if interested.

Reverse Osmosis

Reverse Osmosis is really the 'Rolls Royce' of Water Purifiers. These systems are good if you wish to remove everything from the water, including minerals and fluoride, which are not removed by a carbon-based Purifier. They work on a principal of passing water over a semi permeable membrane. The water passes through the membrane while all chemicals and contaminants are washed down the sink. The water produced by these systems is near pure and similar to distilled water in content, as they are slow to produce pure water (around 3 - 9 litres per hour). They are generally only used as under-sink installations, and use a storage tank to hold the purified water. Bench top models are also possible and are most often installed in the laundry for convenience. Typically these models are used to fill a jug or storage container. If you are interested in one of these, please contact us for further information.

Distillers

Distillation is the process of boiling water and condensing the collected steam back into water again. In theory all the contaminants are left behind in the boiling chamber. Distillers are an option for people who want to remove minerals from the water. For drinking water the condensed steam should be passed through a carbon filter to remove any chemicals which are carried by the steam. The carbon filter also helps to improve the flavour of distilled water, which can have a bitter taste. Some chemicals do have low boiling points and so are actually evaporated with the steam. Distillers are easy to operate and are portable.

Warranty

All urban Water Purifier systems from 'Wellington Water Filters' are covered by a written 3 Year Warranty which protects you from both faulty product and installation. Distillers are covered by a one-year manufacturer's warranty.

THM's

THM 's ( Trihalomethanes ) are a range of toxic chloroform chemicals and are a by-product of the reaction between chlorine and organic material in water. NZ research has shown that 25% of all rectal, bowel and bladder cancers and 25% of all birth defects in NZ can be attributed to these by-products of chlorination. Not all Purifiers are effective at removing these chemicals, and most will only remove them for a short time. A high capacity Carbon Block cartridge or Reverse Osmosis are generally most effective at removing THM 's.