How Does Reverse Osmosis Work? All You Need To Know

how does Reverse Osmosis work

Reverse osmosis is a water purification process that is becoming increasingly popular. It uses a semi-permeable membrane to separate the dissolved salts and other impurities from the water. The process is relatively simple and can effectively remove even the tiniest particles from the water. The result is clean and pure water that is free from contaminants. So, how does Reverse Osmosis work?

Reverse osmosis purifies water and has been used in many industries, including food and beverage production, pharmaceuticals, and wastewater treatment. It is also used in home filtration systems and is gaining popularity as a way to get fresh and clean drinking water.

Reverse osmosis is a fantastic process that is changing the way you get clean water, and it is essential to understand how does Reverse Osmosis work?

FAQs (Frequently Asked Questions) On How Does Reverse Osmosis Work

1. How does a reverse osmosis system work?

A reverse osmosis system first utilizes a pre-filter to remove sediment and chlorine from the water. Then, pushes the water through a semi-permeable membrane, eliminating any dissolved solids. After this, the water passes through a post filter to refine the drinking water before transferring it to a special faucet.

2. Is it healthy to drink reverse osmosis water?

There is no hard proof that drinking reverse osmosis water harms one’s health. If you have a healthy eating plan and do not have any major health issues such as intense heartburn or stomach sores, there will be no difference in your overall health and well-being if you drink water filtered by reverse osmosis.

3. How pure is reverse osmosis water?

Reverse Osmosis is a process by which tap water purifies at 90 to 99%. During deionization, the DI filters replace the positive hydrogen and negative hydroxyl particles in the water with other positive and negative molecules that are contaminants.

What You’ll Need

  • Phillips head screwdriver
  • 1/4” drill bit (for drain saddle valve)
  • Adjustable wrench
  • Box cutter
  • Power drill
  • 1/2” drill bit (for RO faucet)

How Does Reverse Osmosis Work?

How does reverse osmosis work? The reverse osmosis process utilizes pressure to make the feed water pass through a semipermeable membrane, eliminating the contaminants in the unfiltered water. 

The RO membrane allows water to flow from a higher concentration of pollutants to the side with fewer pollutants, thus providing potable water. The freshwater output is identified as permeate, while the leftover concentrated water is brine or waste.

A semipermeable membrane has tiny openings that prevent pollutants from passing through but allow water molecules to move across. As a result of osmosis, the water grows more concentrated as it is transmitted through the membrane to create a balance on both sides. 

During reverse osmosis, pressure is applied to salty water, preventing contaminants from passing through the membrane to the less concentrated side. This pressure enables the salt to remain on one side while only clean water is allowed to go through.

Why Do You Need A Reverse Osmosis System?

Reverse osmosis is a fantastic process that is changing the way you get clean water, and it is essential to understand how does Reverse Osmosis work?

If a water softener or other filtration system is insufficient to satisfy a homeowner’s requirements, reverse osmosis is an excellent alternative. Some people may be perfectly content with the outcome of softened hard water, while others are looking for a clean, filtered bottled water flavor.

How does reverse osmosis work? Other water filtration systems cannot capture all of the impurities that Reverse Osmosis (RO) systems can remove. These systems also referred to as “RO systems,” are better able to eliminate contaminants than other systems. Reverse osmosis drinking water systems have gone through testing and are verified to reduce significantly: 

  • Arsenic
  • Nitrates and Nitrites
  • Selenium
  • Radium
  • Cadmium
  • Total Dissolved Solids (TDS)
  • Lead
  • Copper
  • Chromium (hexavalent & trivalent)
  • Fluoride
  • Barium
  • Cyst (cryptosporidium)

Soft water is great for washing, bathing, and doing laundry. Nonetheless, many individuals do not prefer consuming it. Depending on the hardness of the original water, it may still contain a high level of total dissolved solids (TDS), which can make it unpleasant to taste.

A water softener cannot remove any other pollutants from the water besides the hard minerals replaced by sodium.

An RO system is an excellent fit for many residences since it can eliminate unwanted sodium and other impurities and dissolved solids. Combining it with a water softener is an ideal solution.

How Does Reverse Osmosis Work: Benefits Of Reverse Osmosis System

An RO system is a broad way of filtering, taking out nearly 98% of dissolved solids, resulting in healthy drinking water. The only other method of purification that reduces Total Dissolved Solids is a water distiller, though it is less effective than the RO system.

  • Sodium reduction
  • More environment-friendly than bottled water
  • Perfect under the kitchen sink
  • Harmful dissolved contaminants reduction
  • Bad tastes and odors reduction
  • Easy installation and maintenance

How Does Reverse Osmosis Work: Step-By-Step


Even though I have concisely explained reverse osmosis, there are a few more elements to the process employed to make pure drinking water. A reverse osmosis system consists of three tubes placed side by side on a single base, one of which is a reverse osmosis membrane, and the other contains carbon filters.

Let’s thoroughly examine the aim of each of the three filtration steps and how does reverse osmosis work: 

Step 1: Pre-filtration

The initial stage of refining water with a reverse osmosis drinking water system safeguards the membrane. It filters out bigger sediment, including some dissolved substances, and assists in decreasing the amount of chlorine that may be present in your water.

The initial filter is known as the sediment filter or carbon block filter. It protects the membrane from being blocked by too much sediment or harmed by a high chlorine level, typically found in municipal water supplies.

Step 2: The Reverse Osmosis Membrane

After the preliminary filtration process, the unbelievable power of a reverse osmosis system is revealed. Water is pushed through a semipermeable membrane using pressure.

A reverse osmosis membrane is composed of a fabricated plastic material that can permit water molecules to traverse. On the contrary, substances like sodium, chlorine, calcium, and larger compounds such as glucose, urea, and cysts cannot cross through.

Water-Right typically employs thin-film composite (TFC) membranes, which are impervious to bacterial deterioration and usually have a 95 to 97% rejection rate. However, TFC membranes are not tolerant of chlorine, so a carbon pre-filter is necessary.

Steps 3: Post-Filtration And Final Polish

Before the water from your residence is suitable for consumption, it goes through an additional carbon filter (or post-filter) to eliminate any residual impurities that might have evaded the initial two phases of the filtration process.

Subsequently, the water is brought into a containment tank to be held until you need it. The last step is the in-line activated carbon filter that provides an additional purification layer before it comes out of the tap.

This step is taken to eliminate any off-putting smells or tastes that might still be present in the system pipes or reservoir while the water is waiting to be used. The polishing is an extra precaution to guarantee that the water you drink is delightful!

What Does A Reverse Osmosis System Remove?

A reverse osmosis system utilizes a RO membrane to filter out dissolved substances such as arsenic and fluoride. At the same time, sediment and carbon filtration provide an additional layer of protection against a wider range of contaminants.

The carbon filters in a reverse osmosis system remove chlorine and any unpleasant taste and smell, while the sediment filter catches any dirt or other particles.

The reverse osmosis system removes the following: 

  • Salt
  • Chlorine
  • VOCs
  • Fluoride
  • Sediment
  • Arsenic
  • Herbicides and pesticides
  • Other contaminants

If you get your water from a municipality, it should already be microorganisms-free. 

Reverse osmosis can take out some microorganisms, but there is a risk that bacteria could form on the filtering membrane and make their way into the water.

If you want to remove living organisms & viruses, I recommend UV disinfection.

Space You Need For A Reverse Osmosis System


Reverse Osmosis systems are not bulky compared to other methods like water softeners. The size of the system will vary depending on the model you pick.

Reverse osmosis water filtration systems are installed beneath the kitchen sink, which will only occupy cabinet space. They can be mounted in the basement and connected to the desired sink.

Whole-home reverse osmosis systems require more space than regular models and are near where your home acquires its water supply, such as a water softener or a water heater. These systems are usually installed in the basement or a utility room.

Remember that if you are willing to give up a little room, you will receive a huge advantage, such as improved-tasting water, reduced expenses, and much more!

Maintenance For A Reverse Osmosis System

Take good care of any water filtration system for your house or a specific device. A correctly maintained reverse osmosis system can serve you for up to 10 years or even more!

Suppose you have a reverse osmosis system set up in your residence. In that case, it is essential that the person who installed it goes over the necessary upkeep and the corresponding timetable for maintenance.

The interval for changing the carbon or membrane cartridges relies on the number of pollutants you require to filter out and the quantity of water that passes through the system.

The pre-filter or sediment filter should be switched out once a year to safeguard the reverse osmosis membrane. A local expert may recommend that it be done every 6 months for higher-than-average usage.

If you want to ensure the longevity of your membrane, take proper care of the filter. This will allow you to use it for two to three years before replacement. Changing the carbon filter annually or bi-annually is also advisable, depending on the water quality.

How To Reduce Wastewater In An RO System


Incorporating a permeate pump into a reverse osmosis system is the most effective way to enhance its performance. This type of pump can reduce the amount of wastewater generated by the RO system by as much as 75-80%.

Ensure that the reverse osmosis system is set up for an auxiliary pump, as not all are. When selecting an RO system, choose one with a built-in automatic shut-off valve. This ASO valve will cease water flow to the drain once the storage tank reaches capacity.

It is possible to take benefit of the water rejected by reverse osmosis and use it for landscaping or to create artificial lakes. Even though this water has a higher number of total dissolved solids, it is still secure to utilize in your garden or yard.

The Neo-Pure 4300 DLX is highly effective among reverse osmosis systems as it has both a permeate pump and an ASO valve.

Is Reverse Osmosis Good For The Environment?

Sewage is either directed to a water purification facility to be weakened for simpler processing or to riverbanks for nature to process via the water cycle.

Utilizing a reverse osmosis system improves the effectiveness of waste treatment. The reverse osmosis water discharged from the home is devoid of any chemicals as the carbon filtration step has filtered them out.

The brine water left over has a slightly elevated level of inorganic material that has been dissolved. Reverse osmosis systems facilitate recycling since no new substances are added to the water supply once the RO water leaves the home.

Similar Tutorials Types to Check Out

  • Does Reverse Osmosis Remove Fluoride: Reverse osmosis systems remove various contaminants from water, and fluoride is one of them. In this article, you’ll explore how reverse osmosis removes fluoride from water.
  • Whole House Reverse Osmosis System: A whole house reverse osmosis system can provide your family up to 99% pure water. This article will explore everything about the whole house reverse osmosis system.
  • Water Filters That Remove Arsenic: Investing in a water filter that removes arsenic ensures that your family is drinking clean & safe water. In this article I will show you the 7 best water filters that remove arsenic.
  • Best Water Filter To Remove Calcium And Lime: Calcium and lime can be found in residential water lines & can cause hard water and scale buildup. So, in this article, I am sharing the 8 best water filter to remove calcium and lime.

Summary: How Does Reverse Osmosis Work

Reverse osmosis water filtration is the best way to purify drinking water. Although it isn’t perfect, it can remove most harmful and even toxic impurities from water in a very short amount of time.

The process is effective because it utilizes pressure to create a water-tight barrier, preventing water with impurities from passing through the membrane while allowing pure water to flow through.

You may want to supplement a reverse osmosis system with a carbon filter, as it can also improve the results by removing fluorescence and odors. You know you’ve got the right setup when you’ve got healthy water and good vibes from your faucet.

If you use a reverse osmosis system, you will likely see a reduction of up to 99.99% of harmful dissolved salts and contaminants. You will also notice a reduction of up to 99% of these contaminants in your tap water.

I hope this article on how does reverse osmosis work sounds helpful! Feel free to comment down your opinions in the comments section. Don’t forget to share this article if you liked it. Thank you!

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