Yes, I know many of you know that a reverse osmosis filters
water. However, do you know how
it filters water?
What contaminants it will filter from the water?
How to install a reverse osmosis system?
If you should use other filtration methods with it?
If you have ever wondered about those things, then don’t
worry we will answer those questions, and more, in the following guide.
How does a reverse osmosis system work?
The first step to understanding a reverse system is understanding
how they work.
Reverse osmosis is actually a fairly simple process to
understand. Basically, water passes through a very fine membrane. Contaminants
get stuck in the membrane. The water downstream of the membrane is clean water.
Contaminated water stays upstream of the membrane in a holding tank. When the
holding tank is full the tank is flushed down the drain.
Reverse osmosis systems use no electricity because they use
a mechanical process that simply does not need it. However, they do waste a lot
of water. On average, for every gallon of water filtered through a reverse
osmosis membrane four gallons will be flushed down the drain.
This still works out cheaper because electricity costs less
than the same amount of water. You should keep in mind though that this is not
a “free” source of water filtration though.
What is in a reverse osmosis system?
The typical system will include a sediment filter
pre-filter, the reverse osmosis membrane, the storage tank for contaminants,
and a carbon filter.
What type of contaminants does it filter out?
Reverse osmosis filtration removes just about every type of inorganic material from water. It also removes salt, which most other filtration types cannot (efficiently) remove. Salt removal makes these systems very popular in locations that have brackish water. Brackish water is actually a problem for those that live near the beach.
Reverse Osmosis Filtration Process
The specific contaminants that a reverse osmosis membrane
removes will vary depending on the filter size selected. However, the following
process will explain all the contaminants that the various filters on the system
Sediment Filter: The
first step of the process involves the water passing through a sediment filter.
This removes sediment from the water as the name suggests. Examples of sediment
include sand, dirt, rust (ew gross… I know), and other particulates that you
can physically see in your cup of water. We definitely don’t want any of this
stuff in the water.
filter: The water next passes through an activated carbon filter. This
activated carbon filter is the same kind found in a normal water pitcher
filter. The activated carbon will remove chlorine, pesticides (!), and all
kinds of other chemicals that you DO NOT want in your water. In addition, these
chemicals can damage the membrane of your reverse osmosis system, so they
definitely have to go.
Membrane filter: This stage removes everything else from the water. This
includes salt too as mentioned earlier. Simply put, anything bigger than a
water molecule will not pass through the membrane. This things remove a lot of contaminants.
The filtration process works so well that it removes just about every mineral,
which makes the water a little more acidic. This includes minerals that have
some benefit to humans (such as calcium and magnesium). Some reverse osmosis
systems will add those minerals to the water and make the water less acidic.
Storage Tank: The
filtered water will then collect in the storage tank for use when a faucet is
turned on. This means you will not have to wait for the whole filtration
process each time you want to use water.
This optional phase is when you can have the water move through other
filtration steps to remove further contaminants. One popular step is to have
the water move through an ultraviolet light filter to remove any kind of
microbes, bacteria, fluoride, or other contaminants that the previous filters
do not remove.
carbon filter: The final step involves the water flowing through one last carbon
filter. This removes any dissolved rubber from the storage tank and guarantees
the absolute purest water you can find.
Reverse Osmosis Efficiency
Reverse osmosis systems will remove just about everything
from water as stated earlier. However, this comes at a cost. These filters are
relatively slow compared to a whole house filtration system.
Keep in mind that the storage tank for filtered water
greatly increases the speed of the filtration process.
A reverse osmosis filter efficiently uses electricity as
they use zero electricity. They do use quite a bit of water (4 gallons of water
per 1 gallon of filtered water), but water is much cheaper than electricity.
Just keep that in mind before purchasing a system.
Where to install a reverse osmosis system?
Most homeowners install the system underneath their kitchen
sink and have a little hose that they use to fill up their water pitcher. There
is not much purpose in whole house water filtration with a reverse osmosis
system unless you drink from the bathroom sink on a regular basis or you like
to shower in ultrapure water.
A specifically designed whole house water filter will work
better and more efficiently for filtering water for the whole house.
How to install a reverse osmosis system
Our suggestion is to have a professional install the system
to ensure everything works properly and no accidental contamination occurs.
However, if you insist on installing it yourself, then the following video will
help you out in that process.
Note: A written step by step guide just doesn’t work for
explaining the process. You really have to see it to properly understand how to
Is a reverse osmosis system right for me?
Only you can decide. If you like ultrapure water, then you
should consider purchasing a reverse osmosis system.
We won’t lie to you and tell you that “everyone needs a reverse
osmosis system.” These units use a lot of water compared to other filtration
methods. However, if you really value ultrapure drinking water, then a reverse
osmosis might be the right choice for you.