What Is a Reverse Osmosis System Used for?

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Reverse osmosis systems can be used in a multitude of ways and for a variety of reasons.

The possibilities are endless, from getting the salt out of seawater to eliminating a foul smell or taste from your kitchen water supply to making clear and clean ice cubes.

So, let’s take a look today at all the ways in which RO water purifiers can be used.

Key Takeaways

Reverse osmosis water treatment is used for various residential and industrial applications, but the primary purpose is to provide water free of impurities to various sources, such as:

  • Home drinking water
  • Home bathing water
  • Pharmaceutical manufacturing
  • Food and beverage industries
  • Desalination
  • Wastewater treatment

What Is a Reverse Osmosis System Used for at Home?

So, what is a reverse osmosis system used for at home?

A home reverse osmosis system is a water filter usually used to purify drinking water. The purification process makes water that is free of harmful contaminants and smells and tastes better.

That said, there are three kinds of reverse osmosis systems that can be utilized in the home, which are:

  1. Countertop RO system – A point-of-use countertop reverse osmosis system is compact and portable and typically has fewer filtration steps than an under sink system. It’s designed to sit on top of a counter. Many units connect to the kitchen faucet filtering the water that comes out of it. It is ideal for small spaces or renters, as it requires no permanent installation and can be moved as needed.
  2. Under sink RO system – An under sink RO system has between 3 to 5 filtration steps and may come with or without a storage tank. As the name suggests, these are typically located under the sink and have a dedicated faucet for dispensing filtered water.
  3. Whole house RO system – A whole house RO system is a large-scale water filtration setup that purifies water for an entire home. It is installed at the main water supply point, ensuring clean and contaminant-free water for all pipes and fixtures, including faucets, showers, and appliances. It is mainly used for highly contaminated water rather than municipal water-supplied homes. In other words, a whole house reverse osmosis system not only protects your health and wellbeing but also your plumbing system.

These 3 types of reverse osmosis systems are primarily used in homes but can also be found in offices or commercial kitchens.

Under Sink Reverse Osmosis System

Industrial Applications of Reverse Osmosis Water Treatment

Reverse osmosis water is important for various industrial applications also, such as:

  • Pharmaceutical and food & beverage: Both domestic and commercial sectors rely on municipal water for various applications, including cooking, washing, and pharmaceutical manufacturing. Ensuring water quality is crucial, and RO may be employed to ensure water is free of impurities for use in these industries.
  • Seawater desalination: Marine industrial operations, such as maritime transport and cruise ships, depend on the desalination of saline water for drinking water free of contaminants.
  • Brackish water desalination: Brackish water contains high levels of dissolved salts. For industrial and potable water applications, the World Health Organization recommends water with less than 500 mg/L, so reverse osmosis is often employed to desalinate brackish water.
  • Wastewater treatment: Wastewater treatment plants use reverse osmosis as a purification technique, typically implemented as the final process to completely eliminate any remaining dissolved impurities.

Other Uses of Reverse Osmosis (Water)


Brewers employ reverse osmosis to achieve a water state free of all contaminants, good and bad, and then introduce minerals according to their requirements. For example, during the boiling phase, alkalinity can counteract acids, potentially affecting the taste of the beer. Calcium in the water can result in hoppier or more bitter-flavored beers. Using reverse osmosis, brewers can purify their water and eliminate such impurities.


The quality of tank water is essential when keeping fish. It is vital to regularly monitor nitrate, pH, alkalinity hardness, and ammonia levels. Furthermore, water containing fluoride and other chemicals can be hazardous to fish.

Although numerous products are available for fish owners to assess their water quality, it is advantageous, to begin with high-quality water, such as reverse osmosis water. Reverse osmosis eliminates up to 99 percent of contaminants, including those deemed harmful to aquatic life.

Car Washes

Calcium deposits and residues from hard water leave ugly stains and can damage cars over time. Reverse osmosis water removes up to 99 percent of contaminants, thereby producing cleaner and better results for car washes.


Cafes may use reverse osmosis water not only to serve their guests purified drinking water but for the coffee machine! It reduces scale build-up in the coffee machine.

Lawns and Gardens

Reverse osmosis water can be used to irrigate lawns and gardens as it eliminates salts, heavy metals, bacteria, pesticides, and other contaminants that may harm plants. It also allows gardeners to remineralize the water according to the plant’s needs.

Makes Clearer Ice Cubes

Using reverse osmosis water in ice makers can produce clearer and tastier cubes.

Most under sink reverse osmosis systems can be hooked up to the ice machine on the refrigerator.

How Reverse Osmosis Works

Reverse osmosis uses pressure to push water through an ultra-fine membrane, removing contaminants larger than .0001 microns.

Reverse osmosis works opposite to osmosis, requiring external water pressure to force the unfiltered water through the RO membrane and to become filtered water. If the feed water pressure is too low, RO membranes won’t work efficiently.

RO membranes separate water into two streams: Contaminant-filled wastewater and filtered water. Feed water enters the membrane chamber, and under high pressure, clean water molecules pass through the membrane while contaminants remain trapped. The wastewater is disposed of, and the filtered water continues to the next filtering stage.

If you have any questions about the use of RO water purifiers please don’t hesitate to leave a comment below!

About the Author Gene Fitzgerald

Gene Fitzgerald is one of the founders of BOS and currently head of content creation. She has 8+ years of experience as a water treatment specialist under her belt making her our senior scientist. Outside of BOS, Gene loves reading books on philosophy & social issues, making music, and hiking.
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