What Is A Reverse Osmosis System? Types, Benefits, & More

There are many water filtration and purification methods out there, but you might have heard of reverse osmosis as well. Why it’s a great water filtration system? How does it work? Which impurities does it remove? What are its types? If you have questions like these in mind, this guide is for you.

What Is A Reverse Osmosis Filtration System?

Reverse osmosis systems are everywhere, but what exactly are they? First, you should know what reverse osmosis is. Don’t worry, it’s not very complicated.

Reverse osmosis is essentially a process in which a stronger saline solution moves towards a weaker saline solution through a semipermeable membrane by the influence of energy applied.

Essentially, there are two mediums, one with a higher concentration of minerals and one with lower. The former will move towards the latter by a semipermeable membrane. This membrane only allows some molecules to go through it and stops all others. To do this, a specific amount of pressure needs to be applied that’s higher than the existing atmospheric pressure being exerted on the water.

A reverse osmosis water filtration system works by using a high-pressure pump that applies necessary pressure on the water so that the saline water moves through the semipermeable membrane and the result will be 99% clean water – which is the end goal.

Which Impurities Does A Reverse Osmosis System Remove?

If you’re considering getting a reverse osmosis filtration system for your house, you might need to pump the brakes first. You should know what an RO system removes first, otherwise it will be a waste of money and time.

A reverse osmosis water filtration system removes the following impurities:

  • Salt
  • Chlorine
  • PFAS
  • Fluoride
  • Arsenic
  • Sand particles
  • Suspended sediments
  • VOCs
  • Herbicides
  • Pesticides
  • Lead
  • Heavy radioactive metals

However, the seemingly perfect reverse osmosis water filtration system doesn’t remove everything from the water. It can’t remove live bacteria, microorganisms, and viruses from the water. It can only remove non-living organisms and contaminants from the water. If your water is infested with bacteria and viruses too, then you need to pre-treat the water first through UV light disinfection or chlorine disinfection and then you can feed the purified water into the RO system to get clean, filtered water.

Stages Of Water Filtration In An RO Filtration System

Here are the typical stages of water filtration in a reverse osmosis water filtration system:

The first step of the RO filtration that takes place is known as prefiltration. Prefiltration is a process in which water passes through a bunch of filters to remove sediments, chlorine, and other particles. These filters can include normal filters, carbon filters, and even a combination of both.

The next step involves the passage of water through the semipermeable or reverse osmosis membrane. This membrane is kind of like a screen door that allows the water molecules to pass through easily, but other contaminants stay behind. This is the place where the filtration of water leads to 99% pure water in the end.

Next, as the water gets filtered, it needs a place to stay until it’s consumed. That’s the job of a storage tank. The reverse osmosis water filtration system will continue to work until the storage tank is full. Only after that, it will shut off. So, that’s pretty convenient.

When you’re ready to drink water, the storage tank will feed the water through a final filter, called the postfilter, and this extra step filters the water even more so that you can drink fresh and clean water straight from the faucet. This will render the storage tank empty, so the RO process will immediately kickstart into action again. This is the basic gist of a reverse osmosis system.

Benefits Of A Reverse Osmosis Water Filtration System

There are multiple benefits of reverse osmosis water filtration systems and some of them are as follows:

  • The water will taste very good. Fresh and not salty at all. Water obtained from a reverse osmosis water filtration system is going to quench your thirst while tasting amazing.
  • It is an expensive investment but it saves you a lot of money in the long run from buying bottled water over and over.
  • When it comes to filtered water, reverse osmosis leads to the purest form as the filtration process removes almost all unwanted impurities apart from microorganisms.

Types Of Reverse Osmosis Filtration Systems

There are many reverse osmosis water filtration systems available nowadays. Here are some of them:

Countertop RO System

This reverse osmosis water filtration system is mounted either on top of your kitchen counters or you can even put it on the ground. It’s very compact and easier to install. The only problem is that it takes a bit longer to filter the water because of its size. Other than that, it’s very useful for people who live in small spaces and can’t afford to crowd their already limited space with an RO system and a water tank.

You will love the versatility of this type of reverse osmosis water filtration system and you won’t want to go back.

Under-Sink RO System

Under-sink reverse osmosis water filtration systems are directly attached to the faucets of your sink. Once you turn on the faucet, clean and filtered water will come out. This is also another common type of reverse osmosis water filtration system that people use because it’s nifty, compact, and very easy to install.

However, a downside of this type is that you won’t get clean and filtered water anywhere else in the house. The faucet with which the assembly is attached is the only one with access to filtered water. That can be a bummer for some people.

RO System With Tank

This is a generic type of reverse osmosis water filtration system and the most commonly used one. There is a reverse osmosis assembly along with a large storage tank for holding the clean water in.

It’s very versatile and it’s loved by the masses for a reason. They’re great if you have a lot of space for the water storage tank, but that could be a problem for a lot of people too, since their houses are small and they can’t make do with a small storage tank.

Tankless RO System

This is the most modern type of reverse osmosis water filtration system available as of now. This system doesn’t have a tank, which is convenient for people who have small spaces and don’t want a tank to hog up all of the space.

It is a bit more expensive than a regular reverse osmosis water filtration system, but it does make the water taste fresher because the water is not sitting around in a tank for long periods. It’s also a very fast water filtration system and you can get clean water with a push of a button.


A reverse osmosis filtration system is amazing if you want clean and potable water on demand. They’re getting extremely popular in households. Most people who choose whole house water filtration Meadville use a reverse osmosis system individually or in combination with another water filter.