Water filters: do you need one?

A water filter may improve the taste or smell of your tap water, but be aware of the problems and cost involved.
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  • Updated:19 Oct 2008

05.Problems with your tap water?

  • tapIf your water looks, smells or tastes strange, or if your clothing and plumbing (such as sinks and toilets) become stained by it, use our table, below, as a starting point to narrow down the number of possible causes.
  • Ask your neighbours whether they have similar concerns. This may help to find out whether it's a general supply problem, or one caused by your home's plumbing.
  • Talk to your water supplier about your concerns. If you've recognised a potential problem, tell them — it may help them assess and solve the problem more quickly. Ask them for the latest analytical results of your water supply, and the corresponding Drinking Water Guidelines recommendations.
    If you still have doubts, get a water sample analysed. Your supplier may do that free of charge, especially if there's a health concern.
    Your water supplier may be able to solve some aesthetic problems fairly easily by flushing the mains, while other problems may require more extensive cleaning or repair of the distribution system in your area, or work on your home's plumbing.
  • If you've suffered damage (for example, rust-spotted clothes after a wash) you may be able to negotiate compensation from your supplier.

What's the problem?

Except for micro-organisms and lead, most of these contaminants are an aesthetic rather than a health problem, as long as they don't occur in very high concentrations. 

Problem Symptom Possible cause
Stained plumbing and clothes Red or brown Iron
Black Manganese
Green or blue Copper
Reddish-brown slime in water and pipes Slime Iron (bacteria that feed on the iron cause the slime)
Off-colour water Cloudy Turbidity (fine suspended particles) (A)
Black Hydrogen sulphide, manganese
Red Iron
Brown or yellow Iron, humic and tannic acids
Unusual taste or odour Rotten egg Hydrogen sulphide
Metallic pH (acid-alkaline balance) is too low, iron, zinc, copper, lead
Salty Total dissolved solids, chloride
Septic, musty, earthy Bacteria or algae
Bleach-like Chlorine
Corrosive water Deposits, pitting of plumbing pH, copper, lead

Source: NSF International (formerly the US National Sanitation Foundation).
(A) Air bubbles may also cause water to be temporarily cloudy when it comes out of the tap.

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