Found this, hope it helps:
"4. Distilled water. Distillation is a process by which water is boiled until vapor is produced. This vapor is collected and cooled until it returns to a liquid state. Because minerals are too heavy to be carried by the vapor, the resulting water is completely free of additives. A desalination plant is a perfect example of distillation- salt water is boiled, the vapor is cooled and collected, and the salt and minerals are left behind. However, distilled water is also very unpalatable in its natural state. Desalination plants must also add some minerals in order to make the water usable for general consumers.
Distilled water is perfect for applications where minerals and contaminants would cause problems. Distilled water can be used in irons for steam settings or as coolant for car engines. Because there are no minerals that can stain or build up, distilled water is mostly recommended for use in machinery and cleaning products. It is not particular good to drink distilled water, because it has a tendency to pull minerals out of the bloodstream and other areas. Distilled water is perhaps the cleanest version of bottled water available, but it is not good for human consumption.
5. Purified water. Purified water denotes a process by which contaminants and/or minerals have been removed from any water source. It could be tap water which has been forced through a charcoal filter or water treated with ultraviolet light at the grocery store. The designation 'purified' can be applied rather broadly, so a consumer should not be swayed by its use on a label alone. Distilled water is by definition purified, but it is not a good water for drinking. Spring and well waters may have been filtered or deionized or ozonated, which would make them pure by a looser definition.
There is some controversy surrounding the benefits of 'purified water'. Because the water may have been distilled for purity, it can leech out essential minerals as it travels through the body. Many soft drinks are made with purified water- a fact which disturbs many dieticians and health experts. Because of this natural tendency to pull minerals from the system, purified water is only recommended as part of an overall cleanse with a definite ending point, not as a daily rehydrator or replacement for other sources of water."
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