Reverse osmosis (RO) water filters are becoming increasingly popular in the UK as more households look for effective ways to reduce PFAS, chlorine, heavy metals, limescale and other contaminants in drinking water. In this guide, we explain how reverse osmosis systems work, compare the different types available in the UK, and link to our in-depth reviews and testing.
What Is Reverse Osmosis and How Does It Work?
Reverse osmosis uses pressure to push water through a very fine membrane that can reduce a wide range of dissolved contaminants. Most UK household RO systems also use additional pre-filters and post-filters to improve taste, protect the membrane and reduce substances such as chlorine, heavy metals and some PFAS compounds.
Modern systems are available as under-sink units, countertop machines and models that provide instant hot water. The best choice depends on your available space, budget, water usage and whether you want features such as remineralisation or hot water.
Types of Reverse Osmosis Systems Available in the UK
There are three main types of reverse osmosis system commonly used in UK homes:
- Under-sink RO systems – fitted beneath the kitchen sink and connected to a dedicated drinking-water tap.
- Countertop RO systems – sit on the worktop and are usually easier to install, making them useful for renters or people who do not want permanent plumbing changes.
- Instant hot-water RO systems – combine filtration with heated water dispensing and are useful for tea, coffee and cooking.
Each type has different advantages, so we recommend choosing based on space, installation requirements and how much filtered water your household uses.
Our Reverse Osmosis Reviews and Guides
Waterdrop K19 Review UK
The Waterdrop K19 is a countertop reverse osmosis system designed for households that want purified water without permanent installation. Our review covers filtration performance, usability, running costs and day-to-day use.
Waterdrop G5P700A Review UK
The Waterdrop G5P700A is an under-sink reverse osmosis system with alkaline remineralisation. We tested it in a UK hard-water home to evaluate installation, performance and long-term practicality.
Reverse Osmosis vs Carbon Filter UK
Carbon filters and reverse osmosis systems solve different problems. This comparison explains which contaminants each technology can reduce and which option may be better for your home.
Best Reverse Osmosis System UK
Not all reverse osmosis systems are the same. Our buying guide compares the leading systems available in the UK and highlights the best choices for different households.
Best Water Filter for PFAS UK
PFAS contamination has become an increasing concern. This guide explains which filtration technologies are most effective and compares the best options available in the UK.
Whole House Water Filter vs Reverse Osmosis
Should you filter all the water entering your home or only your drinking water? This guide compares whole-house filtration with reverse osmosis systems and explains the advantages of each approach.
Which Reverse Osmosis System Is Best for UK Homes?
There is no single reverse osmosis system that suits every household. Families concerned about PFAS may have different priorities from those living in hard-water areas or those looking for an instant hot-water dispenser.
We recommend comparing several systems before buying and focusing on filtration performance, annual running costs, installation requirements and long-term maintenance.
Our detailed reviews above will help you choose the best reverse osmosis system for your home.
Frequently Asked Questions
Does reverse osmosis remove PFAS?
Many reverse osmosis systems can reduce a wide range of PFAS compounds. However, filtration performance varies between systems, so it’s important to review independent testing and manufacturer specifications.
Does reverse osmosis remove limescale?
Reverse osmosis can reduce dissolved minerals that contribute to limescale. However, a dedicated water softener may be a better solution for treating hard water throughout an entire home.
Is reverse osmosis water safe to drink?
Yes. Reverse osmosis water is generally considered safe to drink. Some systems also add minerals back into the water after filtration to improve taste.
Are countertop reverse osmosis systems worth buying?
Countertop systems can be an excellent choice for renters and households that want to avoid permanent plumbing modifications.
How much does a reverse osmosis system cost to run in the UK?
Most systems have relatively low running costs, although replacement filters and membrane changes should be included when comparing long-term ownership costs.
