The performance of a particular water filtration product can easily be verified by reviewing the "Performance Data Sheet", which lists all of the contaminants the system has been certified to remove and to what degree.
The law in California and several other states requires that this information be included as part of the company's literature, as well as the ongoing replacement cartridge cost, and that a copy be enclosed with each water filtration device. By comparing each product's contaminant reduction capabilities, system cost and ongoing cost per gallon, it is easy to determine which product is best for you.
It is also important to look at the advantages or disadvantages of other products or technologies even though they are not leading brands; such is the case with reverse osmosis and distillation systems. Although none of the leading brands employ either of these de-mineralizing techniques, as their popularity has declined in recent years, there is an ongoing debate over the healthfulness of de-mineralized water vs. filtered water with trace minerals.
While there are studies that argue both sides of this debate, after 15 years of specialized study in water quality and health, we feel that the benefits of drinking naturally balanced water with its natural trace minerals, just makes more sense.
From a non-scientific perspective, the fact that nowhere on this planet do we find naturally occurring de-mineralized water should tell us that we were not meant to have it. In nature, all fresh water contains traces of natural minerals like calcium, magnesium and potassium, which is what our body is designed to run on. All over the world and throughout time, wherever you find the most contaminant-free, mineral rich water, you find the healthiest, most vibrant civilizations.
On a more scientific level, there are several very credible research reports and books that stress the more recent opinion that long term consumption of de-mineralized water can in fact be dangerous. Dr. Zolton Rona, author of "The Joy of Health", states that "the longer one consumes distilled water, the more likely the development of mineral deficiencies and an acid state." Dr. Paavo Airola, cancer expert and author of "How to Get Well" and "Cancer... Causes, Prevention and Healing" also reports that "long term consumption of distilled water eventually results in multiple mineral deficiencies."
Two very negative things happen when we consume water that has been stripped of its natural minerals. First, because de-mineralized water contains more hydrogen it is an acid, with a pH below seven. Any time we consume an acid substance, our body will pull minerals from our teeth and bones to produce bicarbonate in order to neutralize the acid. Second, it has been proven that when our body fluids become more acid than alkaline the production of free radicals increases, causing increased cancer risks.
Many studies suggest that cancer cells can only grow in an acid environment. This theory seems to be supported by the fact that the areas where people live the longest most disease free lives are the areas that have the most alkaline water, water with the highest mineral content.
Reverse Osmosis and Distillation were first developed over 40 years ago for the printing and photo processing industries, which require mineral free water. Because of the popularity and demand for home water treatment products, many companies have marketed these products as "state-of-the-art" drinking water systems, which they simply are not. Often these products are marketed by using a demonstration that measures the TDS (total dissolved solids), and implies that this measurement shows the systems effectiveness at removing contaminants.