Reverse Osmosis and Distillation FAQ'S
Which of the three methods of water filtration, Reverse Osmosis,
Distillation or Berkey® Purification is the healthiest for drinking purposes?
With respect to the healthfulness of the water, most health experts, that are
up to date on current research, are no longer recommending drinking RO or
distilled water on a long-term basis because these methods strip out all of the
beneficial minerals from the water making the water an acidic "hypotonic"
solution. A chemist will tell you that any time a hypotonic (de-mineralized)
solution comes into contact with a "Hypertonic" (Mineralized) solution, the
minerals within the hypertonic solution will transfer out of hypertonic solution
and into the hypotonic solution until equilibrium is achieved. What this means
is simply that when one drinks hypotonic water, the minerals in the blood and
lymphatic system, which are hypertonic, transfer into the hypotonic RO or
Distilled water that is consumed and the minerals are flushed out of the body
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, and this process repeats itself every time de-mineralized hypotonic
water is re-consumed. 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 reading
will not typically change much unless there are a lot of heavy metals or
sedimentary minerals within the source water.
Is there a way to verify for myself the effects of drinking de-mineralized
Yes, you can check this out for yourself during a short fast. 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
What is the pathological removal capability of an RO system?
With respect to Pathogenic Bacterial removal, Reverse Osmosis does not
remove Pathogenic bacteria and that is why it is often necessary to add an
additional UV light to the system. However, the UV sometimes does not kill all
the bacteria because any turbidity in the water can create shaded spots
preventing some bacteria from being exposed. Typically, the UV is installed
before the bladder tank, however it is in the bladder tank that bacteria usually
colonize. Therefore, if the bladder tank is not sterilized on a regular basis, it
becomes a source for bacteriological contamination that is never exposed to
UV. Additionally, the carcasses of the dead bacteria remain within the drinking
water with an RO system whereas they are removed by the Black Berkey®
Which type of water will have the best taste?
With respect to taste, distilled water will taste flat unless you shake it up
rigorously because the distillation process strips the oxygen from the water.
The taste of RO water is typically very good. The taste of Berkey® purified
water is typically very good unless there is an excessive amount of ionized
minerals in the source water. Even in such circumstances the improvement in
the taste of the water is usually remarkable.
With respect to maintenance, how do the three types of systems compare?
All Berkey® systems are easy to disassemble and clean. Typically the lower
chamber should be washed in ordinary dishwater once per month. The elements
need to be cleaned after 6-12 months of use.
Distillation systems 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 changed at differing intervals from four months up to two years.
This requires that the water pressure be shut off and part or all of the system
to be disassembled for maintenance. Additionally, the bladder tank should be
washed with a chlorine solution at six-month intervals to kill any colonizing
How do the three types of systems compare with respect to cost?
With respect to upfront cost, RO systems typically are the most expensive due
to the cost of the system and the additional expense to have the system
plumbed in. Next in cost would be a distillation unit. A Berkey® system will
typically be the least expensive of the three.
With respect to cost per gallon of water, calculated upon the cost per gallon for
replacement filters and energy costs, Distillation systems and RO systems
properly maintained typically cost between 35-65 cents per gallon. A Berkey®
system typically costs about 1.6 cents per gallon.