Do not fill the kettle with hot water from the tap. It dissolves minerals, including lead, from the pipes much more easily than cold water. Fill your kettle freshly each time you boil it. Repeated boiling merely concentrates chemicals, particularly nitrates. Let the water run for some minutes first thing in the morning. Water hardness due to calcium and magesnium isactually healthier for you than soft water. Soft water is often higher in sodium than hard and can consequently interfere with the electrical impulses responsible for a regular heart beat. Never drink water which has been processed by a water softener.

In an August 1990 report, the Consumers' Association's magazine Which? rated Fileder Ametek HM as the under sink water filter with the best all round performance. It reduces aluminium, lead, iron manganese, organic chemicals and chlorine. Citmart Everpure BW100 was runner up. Unfortunately, no filters are able to remove added fluoride.For jug filters, make sure to clean all parts weekly and keep the filtered water in the fridge, which slows down bacterial growth. In a February 1989 comparison, Which? found that Waymaster Crystal, followed by Boots Water Filter, were best at removing pollutants. Waymaster Crystal, as their ads claim, was the only jug to remove nitrates, albeit only for a short period without having to be replaced..

Reverse osmosis. An under sink filter with reverse osmosis contains a semi permeable membrane which will prevent the entrance into your water supply of most things: bacteria, viruses, hydrocarbons, pesticides and other complex chemicals including fluoride, chloride, detergent, hormones and tannin as well as poisonous heavy metals. It will not remove simple compounds like chloroform and phenols unless it has an additional carbon filter. However, reverse osmosis does leach out the organic minerals, so do ensure that you get a plentiful supply of them elsewhere.

Distilled water.You can opt for distilled water, not the sort sold in bottles at garages, but that manufactured by a fractional distillation unit. It will not leach minerals out of the blood and bones as many of its adversaries suggest. The downside is that distilled water tastes terrible dead and flat.

Bottled spring water. Avoid Viche St Yorre and Badois which contain higher concentrations of fluoride than 1 ppm, the recommended level. Lowest levels of fluoride are in Evian, Goccia, Highland Spring,, Perrier and Prewett's. The Which? 1989 report found that several brands contained more bacteria than tap water. Sparkling water is better on this count.