With respect to the health benefits of the water, most health experts, who are up to date on current research, are no longer recommending drinking RO (reverse osmosis) or distilled water on a long-term basis. These methods strip out all of the beneficial minerals from the water making the water an acidic "hypotonic" solution. When a "hypotonic" (de-mineralized) solution comes into contact with a "hypertonic" (mineralized) solution, the minerals within the hypertonic solution will transfer from the hypertonic solution and into the hypotonic solution until equilibrium is achieved. What this boils down to is that when you drink hypotonic water, the minerals in the blood and lymphatic system, which are hypertonic, transfer into the hypotonic RO or distilled water which you've consumed and the minerals are flushed out of the body upon urination.
In an effort to re-mineralize, the blood and lymphatic systems then begin to scavenge for minerals from other parts of the body, such as bones and other organs. This process is repeated every time you re-consume de-mineralized hypotonic water. Several studies suggest that people who drink de-mineralized water (hypotonic) over a long period of time tend to be more prone to degenerative diseases such as osteoporosis.
Berkey Purification systems do not remove the beneficial minerals from the water but they do extract harmful heavy metals such as lead and mercury as well as sedimentary minerals such as iron oxide. Therefore, the TDS (Total Dissolved Solids) reading will not typically change much unless there are a lot of heavy metals or sedimentary minerals within the source water.
Yes, by fasting for a short period you can check this out for yourself. First check the TDS reading on your RO or distilled water, which should be around 1-3ppm. Then after drinking that water for several days check the TDS reading of your urine. Remember, the TDS only measures minerals not chemicals so any minerals that the TDS meter reads are minerals that are being leached or flushed out from your body.
With respect to pathogenic bacterial removal, reverse osmosis does not remove all pathogenic bacteria such as e-coli and giardia, and that is why it is often necessary to add an additional UV light to the system. Sometimes though the UV does not kill all the bacteria because of turbidity in the water which can create shaded spots preventing some bacteria from being exposed. The UV is usually installed before the bladder tank, however bacteria usually colonize in the bladder tank. Therefore the bladder tank may become a source for bacteriological contamination if it is not sterilized on a regular basis. Additionally, the remains of dead bacteria stay within the drinking water of a RO system whereas they are removed by the Black Berkey purification elements.
As far as taste goes, distilled water tastes flat unless you shake it rigorously before drinking because the distillation process strips the oxygen from the water. The taste of RO water is usually very good. The taste of Berkey purified water is always very good unless there is an excessive amount of ionized minerals in the source water. Even in such a circumstance the improvement in the taste of the water is usually remarkable.
All Berkey® systems are easy to take apart and clean. It's best to wash the lower chamber once a month in ordinary dishwater. The elements should be cleaned after 6-12 months of use, depending on the quality of the source water.
Distillation systems are quite maintenance intensive and need to be soaked and cleaned with vinegar solution to remove the scale, typically after each gallon or two.
Reverse osmosis systems can have up to four filter elements, with each needing to be serviced at least once per year. Since this requires that the water pressure be shut off and part or all of the system to be disassembled for maintenance, it is quite often performed by professional personnel. Additionally, the bladder tank should be washed with a chlorine solution at six-month intervals to kill any colonizing bacteria.
In upfront costs, RO systems are usually the most expensive due to the cost of the system itself and the additional expense of having the system installed by the dealer or a professional plumber. Next in cost would be a distillation unit. A Berkey system is by far the least expensive of the three.
With respect to cost per liter of water, calculated upon the cost per liter for replacement filters and energy costs, distillation systems and RO systems properly maintained typically cost between 9-13 eurocent per liter. A Berkey system typically costs about .32 eurocent per liter.