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Reverse Osmosis FAQ's
Frequently Asked Questions
How effective is reverse osmosis for improving water quality?
Who should consider purchasing a reverse osmosis system?
Specifically, which contaminants does a reverse osmosis system remove?
Beyond reducing health-related contaminants what are some other benefits
a reverse osmosis water system?
Does a reverse osmosis system remove biological
How do I properly maintain my reverse osmosis system?
What does a reverse osmosis system look like and where is it installed?
How do I select the right home water treatment system for my needs?
1. How effective is reverse osmosis for improving water quality?
RO is very effective in reducing a range of home water contaminants. This
is possible because the reverse osmosis membrane is comprised of microscopic
pores which allow the pressurized water molecules, among the smallest molecules
known to man, to
pass through contaminants, and even dissolved ions are left behind. Additionally,
RO systems always include a sediment pre-filter that traps fine suspended
permanently clog the membrane. Most RO systems also include a carbon
pre-filter to remove chlorine, along with other contaminants that may damage
RO membranes and affect
that taste, color, and odor of the water.
Reverse osmosis is a low-energy process, useful for substantially
reducing the complete dissolved mineral content of water. the process
is practical in sizes ranging from a few gallons to million of gallons per
2. Who should consider purchasing a reverse osmosis system?
Anyone concerned about the quality of their home drinking
water -- particularly if they notice taste or odor problems or are aware
of high levels of dissolves minerals in their
water supply -- should consider an RO system. Additionally, RO systems often are
recommended for immune-comprised individuals who could be especially susceptible to
infection from various waterborne contaminants. The Centers for Disease
Control and Prevention (CDC) recommends reverse osmosis as a method for removal
of a dangerous
microorganism cyst called Cryptosporidium. Reverse osmosis
systems, which generally include both and RO membrane and pre- and post-filters,
offer a comprehensive
means of eliminating more than 90 percent of potentially harmful contaminants
in home drinking water.
3. Specifically, which contaminants does a reverse osmosis system remove?
A reverse osmosis system can treat for a variety of contaminants including:
Aluminum, Arsenic, Asbestos, Atrazine, Benzene, Chlorides, Chlorine, Copper,
Cryptosporidium, Cyanide, Fluoride, Giardia, Lead, Mercury, Nitrates, Radium, Radon,
Silver, Sodium, Sulfide, Trichloroethylene, and Total Trihalomethanes. NOTE
4. Beyond reducing health-related contaminants what are some other benefits
a reverse osmosis water system?
There are many benefits to installing a reverse osmosis
system beyond greatly reduced concentrations of contaminants. Cleaner, sparkling drinking water is probably the
most noticeable. Because there is little to alter the RO-treated water's natural
state, the flavor of food can come though without any "chemical" taste.
Brewed items such as coffee, tea, or soups may have a richer, more robust flavor, and
fruit juices and powdered drinks mixed with RO-treated water may taste better, too. Even
ice cubes can take on a crystal clear appearance.
Additionally, because of its low mineral content, using RO-purified water in household
appliances such as steam irons and humidifiers can keep them working longer and more
5. Does a reverse osmosis system remove biological contaminants?
RO systems are capable of removing certain biological contaminants
such as Cryptosporidium
and Giardia. The pore size of the RO membrane along with
the amount of pressure applied to the water will generally determine the
rate of reduction of such
contaminants. The Water Quality Association (WQA) cautions, however,
that while RO membranes are reliable for treatment of a range of health contaminants,
considerations such as tiny seal leaks or manufacturing imperfections may
prevent a unit from offering foolproof protection against biological contaminants
for consumer drinking
water systems. Therefore, WQA suggests that absolute disinfectant (a
reduction of contaminants greater than 99.9 percent) be ensured with cyst-rated
and certified products
and post-disinfection systems such as ultraviolet light. NOTE
6. How do I properly maintain my reverse osmosis system?
The filters of your RO system should be changed periodically. In general, both the re- and post-filters should be replaces about every six
months, or at least annually; however, the maintenance schedules may vary due to local
water conditions, the quality of water being filtered, and the manufacturer's
recommendations. The reverse osmosis membrane normally lasts between 3 to 5 years.
WQA suggests you closely follow the maintenance schedule provided by your
water treatment specialist of the manufacturer to ensure that the system
is in proper working
7. What does a reverse osmosis system look like and where is it installed?
Most RO systems are compact units installed under your sink.
(In some cases, they can also be installed on the countertop). A typical system is comprised of one or more
pre-filters, a reverse osmosis module, a post-filter, and a pressurized holding tank (see
diagram below). The pre-filters trap sediment, chlorine, and other contaminants
before allowing water to pass into the reverse osmosis module. The RO module,
containing the RO membrane, further isolates a range of contaminants before allowing
treated water through the post-filter. The treated water received a final
"polishing" as it flows through the post-filter and into a holding tank
connected to a tap on the kitchen sink. The waste water rejected by
the RO is sent down another line into the drain.
Below is a diagram of a reverse osmosis system.
8. How do I select the right home water treatment system for my needs?
In order to select the product that best meets your needs,
begin by having your water tested to determine its quality and which contaminants
my be present. If you are
concerned about health-related contaminants, you local department of health can recommend
state-certified laboratories to test you water. If you are concerned
about aesthetic contaminants (affecting the taste, smell or odor of your
water), contact Joe Stern Water Conditioning for
a FREE water analysis.
NOTE: In California,
State law requires that any reverse osmosis manufacturer or installer
making specific health claims for a drinking water product must have that
product tested and certified by a State