*taken from a water purifiers website ....
Are there different kinds of water?
Yes. In fact, there are at least 9 different types of water. Let's look at them now.
Hard water: The term hard water is used to describe water that is saturated with lime salts, calcium, magnesium, sodium, iron, copper, silicon, nitrates, chlorides, viruses, bacteria, chemicals and many other inorganic metals and chemicals. Most of the water we drink, which comes from public water systems or private wells, is hard water. Any water that runs through the ground has a certain degree of hardness. The longer it filters through the soil, the harder the water becomes.
Raw water: This is water that the earth's rivers carry to the sea. Each year they carry to the sea 5,000,000 tons of dissolved metals and other unnumbered millions of tons of carbon compunds and factory pollutants. Raw water can be hard or soft - as hard as lime water or as soft as rain water. Its every drop is densely inhabited millions of viruses and bacteria. The government has proved that chemicals dumped into our rivers as raw sewage may cause cancer.
Boiled water: The idea of boiling water originated at a time when the main danger was the possibility of disease organism existing in water supplies. Heating the water to 212 degrees Fahrenheit for several minutes effectively kills harmful bacteria making it safe for human consumption in emergency situations (boiling water does not always kill viruses and cysts). However, modern water supplies can contain excess salts, heavy metals and numerous complex toxic chemicals from industrial and agricultural pollution and most of these are not destroyed or removed by boiling.
Worse, many are actually concentrated if the water is boiled because the purer water vapour is evaporated away. Also, when water is boiled, the dead bacteria remains in the boiled water. Although these dead bacteris do not pose a health problem, such dead materials furnish a fertilized soil for rapid and lusty propagation of germs. Boiled water may avoid live disease germs, but still takes on bacterial soil for the growth of other bacteria. While raw water is an aquarium, filled with deadly micro-organisms, boiled water is a graveyard of dead germs.
Natural water (from rain or snow): Soft rain water which has been distilled by the sun should contain no metal matter and no germs. But, when it falls from the clouds as rain or snow, it falls through air filled with bacteria, dust, smoke, chemicals, mud and metals. By the time it reaches the earth as rain water, it is saturated with decaying matter, dirt and chemicals, such as sulphuric and nitic acid. Alas, the term acid rain. To really understand this, all one has to do is look at snow. Snow also picks up metals, chemicals and fallout. Even though snow looks white and clean, it contains as many germs, metals and pollutants as rain water. Remember, freezing does not destroy bacteria.
Filtered water: Filtered water is water which has passed through a very fine strainer called a "filter". The use of a filter to cleanse water is very popular. The general public is led to believe that filtered water is purified water. While it is true that some solid particles are removed from water through filtering, there is no filter made which can prevent bacteria or viruses from passing through its fine meshes. Because filters have no way of ridding themselves of the decaying bacteria, it tends to accumulate at the bottom of the filter. This decaying matter forms an excellent breeding ground for more bacteria. After the filter has been used for several days, the filtered water often contains more disease germs than the water which originally passed through. Water filters, as a rule, become less effective the more they are used.
Mineral water: Mineral water is hard water which is drawn from certain mineral springs. These mineral springs are known for their medicinal effects. But, in fact minerals in water exist as mineral salts or so called inorganic minerals. This form of minerals is not nearly as biologically acceptable to the human body as are organic forms of minerals found in all foods and quality mineral supplements. Some inorganic minerals are harmful to human health (sodium, nitrates, sulphates and toxic metals) and no water treatment process can separate those from the inorganic minerals that are not harmful.
Spring water: There are also hard waters which are called spring waters- that is, waters from certain underground springs. Practically, all kinds of bottled water is spring water. Spring water may be bacteria free because water is drawn from deep underground springs, but it is saturated with lime salts, calcium, magnesium, sodium, iron, copper and other inorganic metals. All spring water is hard water because any water that runs through the ground picks up a certain amount of hardness.
De-ionized water: Water processed by the de-ionized method effectively removes metals and other inorganic minerals, and compares favorably to distilled water. De-ionization is a chemical way of purifying water and although it is pure, it is an expensive way of water purification for the home. Care must be taken not to contaminate the purified water because it does become a breeding ground for bacteria, pyrogenic matter and viruses.
Distilled water: Distillation is similar to nature's own way of producing water by way of vaporization and condensation resulting in distilled water. It is a virtually pure form of water that has been heated to boiling, creating steam vapour, leaving behind the vast majority of contaminants. At the same time, it kills viruses, bacteria, giardia and other forms of micro-organisms. When the steam vapour is recondensed, the result is a virtually pure form of water without contaminants. This process is the most effective purification system in ridding water if bacteria, chemicals and inorganic minerals including toxic organic substances. Lab tests show nil amounts of impurities such as calcium, chlorine, sodium and nitrates. Distilled water is so pure and safe that the U.S. Department Of Agriculture endorses a distiller as "the only proven way of correcting drinking water pollution in the home".