Reverse Osmosis Water Filter Systems: All You Need To Know

A reverse osmosis water filter system.

If you’ve ever wondered ‘what is a reverse osmosis water filter system’ this article should help.

A modern reverse osmosis water filter system combines membrane filter technology with carbon and mechanical filtration to produce highly purified, improved-tasting drinking water.

They sound complicated and a bit like something you might find in a chemistry lesson!, but if you’re are looking for an effective water filter system for your home, they’re  a popular choice with consumers and less complicated to install and use than the name might suggest.

Check out my Top 3 Rated Reverse Osmosis Water Filter Systems here

How Does a Reverse Osmosis Water Filter System Work?

Standard reverse osmosis water filter systems require no electricity and use household pressure to pass water through a semi-permeable membrane.

All reverse osmosis water filter systems work in the same way and look alike, with the same or similar basic components. The main difference you will find is the quality of the filters and membranes inside the filter and the number of stage of filtering.

A reverse osmosis water filter system works by pushing water from the tap through a membrane and filter (or series of filters). Only the water passes through the membrane, leaving any larger molecule impurities behind. The pollutants are disposed of via the drain and the fresh water passed to a holding tank, which can easily be accessed via a tap.

A reverse osmosis water filter system unit can be installed under the sink or in a remote interior location, as long as there’s a water supply and drain point nearby.

They’re a popular choice for a home water system due to there ability to generally filter out more contaminants than many other types of filter, but often still at a reasonable cost.

What does a Reverse Osmosis Water Filter System Remove?

Reverse osmosis will generally remove any molecular compounds smaller in size than water molecules.

Like distillation, though, reverse osmosis removes almost everything from water, both good and bad.

A top quality reverse osmosis water filter, such as the highly rated APEC systems are able to filter  out up to 99% of contaminants including:

  • arsenic
  • chlorine
  • lead
  • fluoride
  • heavy metals
  • bacteria and viruses
  • plus agreat many others.

Reverse osmosis is also effective with taste and odour-producing chemicals, particulates, total dissolved solids and turbidity.

When activated carbon pre-filtering is also used in combination with the membrane (it is in top modern systems), water can also be effectively filtered against volatile organic compounds (VOCs). 

You may have read that some reverse osmosis filter systems fail to remove chemicals such as chlorine and pesticides. However, most modern systems use a carbon filter, in addition to the membrane, which does remove these contaminants. To be sure, though, always check the product details.

Whilst one reverse osmosis filter system may look very much like the next, it is important to do your research. Whilst the design and components may look similar or the same across different brands and models, it is the quality of those components that is key. Differences in the quality of the components can have a significant impact on the quality of the water the system produces.

It’s also advisable to check that a filter meets the NSF seal of approval, or similar, as this indicates the filter has been independently tested to show it can reduce levels of certain pollutants under specified conditions.

Pros of a Reverse Osmosis Water Filter System

A reputable, good quality reverse osmosis water filter system will:

  • remove almost all contaminants from water
  • provide better tasting, purer drinking water
  • offer good value for money
  • be easy and convenient to use
  • generally last a long time (some sources suggest a lifetime) as long as you service it regularly and replace the parts that wear out, such as the storage tanks (membrane typically last around 3- 5 years)

Cons of a Reverse Osmosis Water Filter System

Reverse osmosis water filter systems are not for everyone. The main drawbacks of reverse osmosis filters are that they:

  • create some waste water, which can be an issue if you are water conscious. Although if you break the waste water down it is probably only the equivalent of 2-3 extra toilet flushes a day.
  • are not selective in which minerals they take out, since reverse osmosis generally removes any molecular compounds smaller in size than water molecules. This means some essential minerals can get filtered out too, as well as the ‘bad’ ones. However, bear in mind, minerals in water are inorganic and harder for your body to use – we actually get most of our minerals from food, which provides organic, easily assimilated minerals. 

The mineral question is one of the most controversial in the whole drinking water purification arena, with experts sometimes citing convincing arguments on both sides. So at the end of the day, this is a personal decision.

Not all reverse osmosis water filter systems are able to remove pollutants such as chlorine or pesticides either, since they are molecularly smaller than water. So check the system has a carbon filter stage, as this will effectively tackle these contaminants. Top rated reverse osmosis water filter systems will almost certainly do this as a matter of course, but it’s best to check.

In Summary – What is a Reverse Osmosis Water Filter System?

Reverse osmosis water systems for the home are one of the most effective and common options for providing good tasting, pure, drinking water through the reduction or removal of most contaminants.

They do create some waste water and also remove some of the good minerals in drinking water, but whether either of these factors are an issue for you, when deciding upon the right water filter for your home, is really down to personal choice.

Remember, always, read the small print or product details to check which contaminants a filter removes, so you are clear what you are getting.



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