What Does Reverse Osmosis Remove?

A reverse osmosis water filter uses a semi-permeable membrane to remove impurities from water. The process of RO filtration works by applying pressure to water in order to force it through a series of filters and membranes, leaving impurities behind.

Reverse osmosis filters are commonly used in homes and businesses to remove a wide variety of contaminants from drinking water.

What Does Reverse Osmosis Filter Out?

reverse osmosis system with activated carbon filtration system in ro membrane

Reverse osmosis (RO) water filter systems remove a wide range of impurities from water. The membranes and filters act as barriers, allowing water molecules to pass through while trapping larger particles and impurities on one side.

One of the main impurities that RO systems remove is dissolved solids, such as salt and minerals. The membrane is able to remove up to 98% of dissolved solids, leaving the water with a much lower conductivity. This can be beneficial for people who live in areas with high levels of dissolved solids in their water, as it can help to improve the taste and odor of the water.

RO systems also remove a wide range of other impurities, including microorganisms such as bacteria and viruses, as well as larger particles like sediment, sand and rust.

They also effectively remove many of the dissolved contaminants such as lead, chlorine, fluoride, arsenic and other dissolved heavy metal.

In addition to these impurities, RO systems also remove dissolved gases, such as carbon dioxide and hydrogen sulfide. These gases can contribute to the taste and odor of water, so removing them can improve the overall quality of the water.

Finally, RO systems can also remove a wide range of organic compounds, such as pesticides, herbicides and other chemicals that may be present in water. They are also effective at removing many dissolved organic materials such as dissolved natural organic matter that are not removed by conventional filtration methods.

In summary, Reverse Osmosis (RO) water filter systems are effective at removing a wide range of impurities from water, including:

  • Dissolved solids
  • Microorganisms
  • Sediment
  • Dissolved gases
  • Organic compounds

This makes the water safer and more palatable to drink.

It’s worth noting that reverse osmosis water filters also remove many beneficial minerals, such as calcium and magnesium, which are found in tap water. Many companies that sell reverse osmosis systems offer an additional filter or add-on that can add these beneficial minerals back into the purified water.

How Does an RO System Work?

reverse osmosis process; reverse osmosis system work with activated carbon filters in ro unit for household drinking water pressure

The basic components of a reverse osmosis filter system include a pre-filter, a reverse osmosis membrane and a storage tank.

The pre-filter is designed to remove larger particles such as sediment and dirt, which can clog the membrane and decrease its efficiency.

The reverse osmosis membrane is the heart of the system and is designed to remove dissolved minerals, bacteria and other contaminants from the water.

The storage tank is used to store the purified water until it is ready to be used.

The reverse osmosis membrane is a thin film of material that is selectively permeable, which means that it allows some molecules to pass through while blocking others. The membrane is made of a material called a polymer, which is a large chain of repeating units.

Maintenance Requirements

Reverse osmosis filters require regular maintenance. The pre-filter will need to be replaced periodically, depending on the level of contaminants in the water.

The reverse osmosis membrane will also need to be replaced periodically, usually every 1-2 years.

Additionally, the storage tank will need to be cleaned and sanitized regularly to prevent the growth of bacteria.


Overall, reverse osmosis water filters are highly effective at removing a wide variety of contaminants from drinking water.

These filters use a semi-permeable membrane to remove dissolved minerals, bacteria and other pollutants from water.

They have several advantages over other water filtration methods, including their ability to remove dissolved contaminants and their relatively low cost of maintenance.

However, it is important to remember that reverse osmosis filters also remove beneficial minerals from water, and that they require regular maintenance to keep them working effectively.

Fortunately, most RO system companies offer add-ons that add these materials back into the water, and maintaining your RO system is relatively easy.

If you want a safe and effective way to filter your water, reverse osmosis is a great option.