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Basic Components of a Home RO Filter System

It’s ironic how the water planet is facing water scarcity! Water scarcity and water pollution have introduced the world to impure and contaminated water.

But who wants to drink unhealthy water if you have the option to make it safe and healthy? RO Filter system is one solution to all the harmful bacteria, pathogens, and chemicals making the water unsafe to drink.

Nowadays, most houses have RO installed in their kitchens. However, most people lack knowledge on what is RO, its components, and how it works?

Well, this article has got you covered with components of a home RO Filter system and its functions. So, let’s get started.


What is a RO Water Purifier?

In the 21st century, short forms travel at a higher speed than their actual names. Similarly, RO is also a short form of Reverse Osmosis.

It got its name due to the Reverse Osmosis technology it uses, which can remove even teeny-tiny impurities, smell, and chemicals from the water.

A regular home RO water purifier has four stages of purification:

  • Sediment Filter
  • Carbon Filter
  • RO Membrane
  • Polish Filter

After completing all the purification stages, it produces safe, healthy, and chemical-free water. RO is also capable of removing the funny odor, taste, and color from the tap water.

The only significant disadvantage of RO is that it wastes a lot of water while purifying it. Do you know? Most of the RO filters produce 1 gallon of filtered water at the cost of 4 gallons of wastewater. That is why RO’s are considered harmful to the environment.

Otherwise, a Reverse Osmosis water purifier is the most effective and efficient purifier in removing all the impurities of the water.


Components of a Home RO Filter System

a Home RO Filter System

Now, we should come back to our main topic, i.e., the components of a Home RO Filter System. Before buying anything, we should always know what it constitutes.

Note: There are various types of RO, such as Industrial RO; here, we are talking about the components of a regular Home RO.

Here are the components and their functions in a Home RO Filter System.

Water Supply Connector

Water Supply Connector

A water supply connector, in-valve, Feed Water Supply Adapter, cold water line valve are all the same and perform the same function. You can call it whatever you want!

It is the water source for the RO as it connects the RO with the house’s cold water supply. Manufacturers of RO have a variety of fittings and valves that best suit the plumbing system.

It comprises a tube through which water travels to the next component, i.e., Pre-Filter.


Pressure Regulator

Pressure Regulator

Pressure Regulator is an optional component which means that some RO has it, some do not. As the name suggests, it helps in regulating the water pressure to protect the pre-filter housings.


Sediment Pre-Filter

Sediment Pre-Filter

Sediment Pre-Filter is the first component in terms of filtering the water. It filters out all the sediments, sand, grit, insoluble iron oxide, precipitated mineral particles, and other debris that can choke the RO Membrane surface, causing less water production.

Experts suggest replacing the sediment pre-filter every 3-6 months.


Carbon Filter for Chlorine and Chloramines

Municipal Water Treatment adds some amount of chlorine or chloramine as a disinfectant of water. Both chlorine and chloramine protect the water from harmful and ill-causing microorganisms.

However, chlorinated water can damage the RO filter system over time. Thus, it is essential to remove chlorine and chloramine in the initial stages.

Carbon Filter has proven to eliminate all sorts of chloride ions and make the chlorinated water chlorine-free.

Note: Not every RO has both a sediment filter and carbon filter.


Auto Shut-Off Valve

Auto Shut-Off Valve (ASO-Valve) conserves the water by restricting the water supply to the RO Membrane.

When the water tank gets 2/3 filled, the ASO valve cuts the water supply till the tank drains out to 1/3 of the feed pressure.


RO Membrane

RO Membrane is an essential component of RO that does 95% of the work in purifying the water. It eliminates most solids such as salt, minerals, chemical compounds, and other harmful microorganisms.

Reverse Osmosis splits the water flow into two areas: Filtered water goes into the storage tank while rejected water goes into the drain.


Check Valve

Check Valve prevents the RO Membrane and filtered water in the storage tanks. When the ASO valve stops the water flow, filtered water flows back from the tank to the membrane.

It can damage the RO membrane; that is why the check valve gets installed right after the RO Membrane in most RO filters.


Post-Carbon Filter

Post-Carbon Filter

Post-Carbon Filter applies the adsorption process through which even little chemicals causing any strange odor, taste, and color in the water get attached to the carbon filter surface.

It enhances water taste as the water flows through a carbon filter very slowly, making it more effective.


Pressurized Water Storage Tank

Storage Tank stores all the filtered water until someone turns the water faucet on to drink water. It is called a pressurized water storage tank as it provides water when it gets pressurized through the tap.


Drinking-Water Faucet

The water Faucet is the last component of the Home RO Filter system. It is a controllable tap attached with the RO through which the filtered water comes out.

Most RO systems come with non-air gap water faucets. However, some that come with air gap faucets have a separate drain line connection.



All the components mentioned above are the essential components present in most home RO Filter systems to purify the water completely.

However, the latest and expensive RO filter systems have extra components such as Pressure Booster Pumps, UF Filters, UV Filters, etc.

So, before buying any RO, ask about their components and purchase what is the most suitable for you!

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