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Reverse Osmosis System

1 x High Quality Reverse Osmosis Water Filter

Get Beautiful Tasting, Incredibly High Quality Filtered Water, On Tap, 24/7

Easy Self-Installation Under Sink - No Plumber Required

Kit Includes Everything You Need

Free Help and Support

Todays Price
£287.00INC VAT
£91.00 (-24%)
Our Usual Price
£378.00 INC VAT
In stock | Only 164 left at this price | Next Day Delivery
Free Delivery & Returns
Order before 3pm for same day dispatch today

"Fantastic service. We have had our filter 8 plus years. It's been the best water filter ever !! I taste water at work and ugh !! The water from our reverse osmosis is incredible. We have replaced filters etc and the service is amazing. I just can't fault this company. We had a drippy problem recently and Jon has been more than helpful in helping us locate and solve the problem. Thank you Jon and to everyone else we have ever dealt with at UK waterfilters. It's a pleasure ordering from you :) "

UK Water Filters Promise
If you change your mind about your purchase, for any reason, within 90 days, you can return your product for a full and complete refund. PLUS we will pay for your return postage (UK)

All orders shipped same day before 3pm

Free Delivery & Free Returns

(We’ll even pay your postage!)

3 Year full parts warranty

What you get
Product Description

Reverse Osmosis Water Filters UK

Reverse Osmosis: The most efficient, powerful way to purify your water

If you want to remove a wide range of problem contaminants from your drinking water - like pesticides, bacteria, microplastics, microfibres, heavy metals, fluoride - and many other pollutants - Reverse Osmosis is, without question, your easiest and best solution.

Plus you get great tasting, healthy water!

Read on for full details, plus useful information and tips on what to watch out for when looking for an RO filter.

My overall experience has been amazing ! My RO water filter arrived really quick. Ed was a dream in helping me with any queries. I can't recommend this company highly enough. I absolutely love my filter. Thank you Rachel J.

How the Filter Fits into Your Kitchen

The filter is designed to fit easily under a standard kitchen sink.

To serve your fresh, purified drinking water you can either get a stylish, small extra tap on your counter top, which you use when you want to drink. (This is supplied as standard with your kit).

Or you can get a "three way tap" - which gives you hot / cold and filtered water. (Here's the three way tap we can supply you with but the system can be used with any make of similar tap. Please ask us about the latest deal if you'd like to get your new RO unit with the 3 way tap).

Reverse osmosis filter fitting into kitchen under the sink

As you may already know, Reverse Osmosis filters are usually expensive. You can easily pay £400 plus.

However, even though our filters are of a higher quality than many on the market, we are offering them to you here at a Special Offer price of £378 - See Today's Special Offer at the top of the screen.

Read on for further details...

Why are These Cheaper than Others on the Market?

Well for a start some people are simply overcharging. They are using the classic sales approach that "if it's expensive it must be good".

Yes, Reverse Osmosis is good. But it doesn't need to be that expensive.

Plus we only sell on the internet. Unlike other retailers, we don't have to pay for expensive shop rents and rates. And we don't add unnecessary "stages" to our RO systems.

Read More

Pros and Cons of Reverse Osmosis

What about "Wasted Water"

Important Note about Acidic water

What about the Minerals?

List of Contaminants Removed by Reverse Osmosis

Installing the System

Replacing the Filters

How Reverse Osmosis Works

What are Reverse Osmosis Stages?

Summary of Features

Pros and Cons of Reverse Osmosis

Pros: RO filtration gives you very high quality water. It removes just about every contaminant you can think of.

Cons: They are more expensive than a standard water filter.

Is it Overkill?

To be honest British tap water is usually good quality. Many people simply want to remove basic contaminants like chlorine in order to get "mineral water" quality for a fraction of the price of bottled water.

Many dangerous contaminants, like bacteria, are taken out by the water treatment plants.

However, other contaminants can get left in the water which RO will remove and a standard water filter won't.

The main reason for choosing an RO unit would be if you wanted to remove a specific contaminant from your water, for example fluoride or hormones or microplastics - among many others.  

Or perhaps you would like an RO to help with an allergy or other medical condition.   

Otherwise, if you are simply looking for a good quality water filter, you might be best opting for one of our "Master Purifier" undersink systems.

This is because the initial purchase and ongoing cartridge renewal costs are much lower than an RO.

For example, at the time of writing, the RO is on sale for £287 vs the Master Purifier at £87.

The replacement filters for the RO are £39.95 every six months vs around £13 for the Master Purifier.

If you do want an RO, please note that we sell very high quality ones at about half the price of many other suppliers.

Be wary about cheaper products though. While ROs do remove nearly all micro-organisms, cheaply made and/or deteriorating parts can greatly increase the risk of contamination through tiny leaks within the system.

UK Water Filters have always offered a great service with excellent after sales service. This is a great product which we have used for many years now. It pays for itself over and over. Steve


The Issue of Waste Water

As part of the Reverse Osmosis filtering process about 70% of the water is rejected / wasted.

While this is only lost from your drinking and cooking water - i.e. not all the water you use in your home - in these times of water meters and general environmental awareness, this may be off-putting.

The "waste / rejected water" is automatically sent down the drain. However, you could recycle it e.g. for garden watering.

(You can read more details about this in the quick article about What are the added costs of wasted water with your Reverse osmosis system

Important Note about Acidic Water

One of the side effects of filtering water with Reverse Osmosis is that it can make the water more acidic.

In the natural health and alternative medicine communities, excess acid / "acidosis" is considered to be an underlying cause of many degenerative diseases.

(Interesting fact: Dr. Otto Warburg won the Nobel Prize in 1931 for his research into the causes of cancer. He claimed it was caused by a lack of cellular oxygenation resulting from acidosis in the body).

In the Far East - where Reverse Osmosis filtration is very common - re-alkalisers are fitted to RO units as standard, to prevent acidicity.

Unfortunately, this is not the case with the great majority of Reverse Osmosis suppliers in the UK and because of this our Eastern friends think, frankly, that we are crazy.

(We only found out about this issue by chance, at a trade fair, during a casual conversation with a Far-Eastern manufacturer. None of our British suppliers had ever mentioned it).

Since then we now supply re-alkerising media as standard with all our Reverse Osmosis systems. It may lower our profit margin but we prefer to follow the "precautionary principle" and sleep soundly at night!

The re-alkaliser media makes the filtered water more alkaline.

It is also thought to result in water that's better at flushing out toxins and waste matter from the body whilst restoring the electrolyte balance.

Please note: If you don't want the re-alkerising media that's fine. Simply ask us to remove it.

How Much Does it Reduce the Acidity?

This depends on how acidic your source water is. But our re-alkaliser will have a significant effect.

You can expect your pH level to rise to at least 6 or more (pH 7 is neutral. Anything higher is alkaline).

What About the Minerals?

A common claim about Reverse Osmosis is that the filtration method is so powerful that it strips the water of everything including essential minerals like calcium and magnesium.

While this usually tends to be put about by people who are selling alternatives to Reverse Osmosis - which are usually not as well proven and, funnily enough, often a lot more expensive - it is actually true.

But here's the thing: they often get the crucial detail wrong.

They usually assume the problem is that by not getting the minerals in your drinking water you're thereby becoming mineral deficient.

But that's not the actual problem.

The real problem is arguably worse than that. What happens is that de-mineralised water will aggressively seek to absorb new mineral molecules.

So when you drink RO - and other types of "de-ionised water" - it might be stripping away minerals from inside your body.

While demineralised water is common in nature - it's called rainwater and has been drunk by humans since, well, forever... - even before we started throwing things at each other - calcium and magnesium deficiency can lead to a range of health issues including pregnancy disorders, cardiovascular diseases and a higher rate of bone fractures.

But here’s a couple of reassuring facts:

Fact one: An easy solution to the issue is to simply re-mineralise the RO purified water before using it.

That’s why we include high quality re-mineralising media along with the re-alkaliser media. Problem solved.

Fact two: In any case, a good varied diet with lots of fruit and vegetables should ensure you have more than enough minerals to cope with any risk of mineral deficiency. An apple a day will certainly pack your body with more than enough minerals to keep the doctor away.

But again, as above, if you don’t want the remineraliser / realkaliser filter simply let us know and we can exclude it from your kit.

It's 10 years now since I had cancer and the reverse osmosis filter is one of the things that has kept me well. I have to say that it has really made me happy the way you deal with people. Gives me hope there could be a better world. Barbara C

How Hard is it to Install the Filter?

Everything you need is in the pack.

It's very easy to install. No plumber is necessary.

You might prefer to use a plumber. If so, this should be a simple, "one hour callout" job for them at most.

(If you're going to hire someone else to do it, we suggest you use a handyman - they'll probably be cheaper than a plumber - and just as good at what is a very straightforward job).

Otherwise, it is all designed to be done by a householder. Full instructions are included. It should only take you about an hour. You will need a normal electric drill. That's all.

And we've got friendly (and free) customer support available.

After much research I decided to purchase a reverse osmosis unit from UK Water Filters and have found the product very easy to install and excellent service if any problems - really do know what they are talking about... good after-sales service. Very pleased and great to have fresh tasting water once again. Maggie

Replacing the Filters

Like all water filters, you will need to replace the filters on the system periodically to ensure maximum performance.

You need to change four of the filters every 6 months. We send you a reminder. The cost for the full replacement kit is £39.95.

Replacing these is very easy and will take a few minutes at most

Every 3 years or so you will need to change the membrane.

The cost of a new membrane is £79.

All the required filters are included when you purchase the RO system.


Please note: This sale is for a limited number of units. So Get One Now and Save!

Read about how Reverse Osmosis works

For full performance details of our RO units please click here.

Supplied complete with all fittings and ready for immediate installation - including tap.

Features Summary:

  • Everything you need to install the system is supplied
  • Simple installation no plumber needed
  • Full instructions included
  • Easy to use
  • Reliable operation
  • Free Technical Helpline to assist with any problems
  • No Quibble ONE YEAR Money Back Guarantee
  • Buy with complete confidence
  • Five year full parts warranty
  • Easy to use
  • Compact design
  • Failsafe flow restrictor
  • Auto shut-off/on full tank
  • State-of-the-art TFC membrane
  • Plus 4 top quality cartridges


With FREE Delivery

Immediate Dispatch

Purchase with Total Confidence

Money Back Guarantee

Click here for delivery information

No hidden extras

If you don't like what you get, send it back for a full no quibble refund.

If for any reason you decide to return your purchase we promise you a no questions asked THREE MONTH Money Back Guarantee. Click here to read the "large print" about our Money Back Guarantee.

PLUS We'll even pay your return postage !

Please order now to secure today's sale price.


Product Code: RO-UKWF

Reverse Osmosis Kitchen water filter
Technical Information

Basic Tech Summary


How Much Water Does it Produce?

List of Contaminants Removed by Reverse Osmosis

Installing The System

Replacing The Filters

Water Pressures

Hot Water

RO Tank Material

Changing the Cartridges

Basic Summary

Everything you need to install the system is supplied

Easy to install no plumber should be required

Full instructions included

Free Technical advice to assist with any problems

Capacity / Production Rate - Gallons Per Day (GPD) 50 Gals

Feed Water Pressure 2.7 bar min to 6 bar max

Feed temp (Degrees C) 4 to 29

Weight 16kg

Main Unit Dimensions

RO unit: 43.5cm High x 35cm x 12.5cm

Storage vessel is 40cm High x 27cm wide

The 12 Litre Tank / Storage Vessel (Freestanding, connected to RO unit by tube, can be placed several yards away - simply ask us for some extra tubing).

Tap Dimensions

(This tap comes with the unit but you can easily use a different type eg a Three Way Tap )

Spout Reach: 120mm

Height: 240mm

Shank length 70mm (ie under counter)

Tp52 Dimensions

Countertop base disc width is 44mm ie you need 22mm clearance on all sides from the middle of the drilled hole

(Or, if you're short of space, you can remove the base disc to be left with a nice looking 20mm diameter tap base).

Notes on Your Water Supply

The unit should be fed by a water supply that is potable i.e. drinkable.

Please note that Reverse Osmosis is a complex process requiring reliable equipment performing under high pressure. Always know where your water main stopcock is located in the unlikely event of leaks.

The filter system doesn't have to be at a level below the tap and neither does the tank as long as it's not a gravity fed system.

Back to Technical Contents

How Much Water Does it Produce?

This model will produce 50 GPD ie its "production rate" is 50 gallons per day.

(This assumes perfect conditions ie clean water at the right temperature and that incoming pressure is good).

But when considering how much water is produced by any Reverse Osmosis filter, the most important factor is the size of your RO tank.

This is because your system feeds the tank then stops when it's full.

Here's how it works: When you draw water from your RO you are taking water from the tank. As the tank empties the system refills it at the "production rate" (ie 50 GPD) up to the tank's capacity.

Now, in addition to this, you have to consider that the tank's size is based on the actual physical dimension and not the amount of water it contains.

You have to also take into account the internal bladder that holds the water inside of the tank.

For example, the bladder inside this unit's nominal 12 litre tank will actually hold between 5 to 9 litres of water. If you draw all the water out of the tank it will take anywhere from half an hour to 4 hours to fill up again - depending on incoming water pressure.

Therefore the amount of water this size produces is 5 to 9 litres per average of 2 hours - on a stop/start basis. (Note that you only have to wait for more water if you fully drain the tank in one go. In our experience this happens very rarely with normal domestic usage).

Other typical tank sizes and the actual water they hold are:

18L nominal tank size: Holds 12 to 15 Litres

40L nominal tank size: Holds 23 to 28 Litres

For High Flow / High Capacity Reverse Osmosis systems click here

Back to Technical Contents

Is Your Water Pressure High Enough?

The unit is designed to operate between 40 psi (2.7 bar) to 84 psi (5.8 bar) (psi = pounds per square inch). Please note that the only problem you are likely to encounter with operating a Reverse Osmosis unit in your home is if the water pressure is not high enough. The vast majority of UK homes have water pressure that is higher than the required 40 psi.

If you think you have low water pressure just do this quick and easy check.

How To Check Your Water Pressure

The simplest way to check your water pressure is to turn your cold water tap in the kitchen on full. Stand a few feet away. If you are being splashed with at least a few droplets then your pressure should be high enough.

If this is not happening you should call your local water supplier. They should be able to tell you what your water pressure is and whether it is likely to drop below 40 psi at any time.

Please note: Local water pressure can change - for example as a result of local road works etc. If the unit stops producing as much water as before check if your pressure has changed.

If you think there are any issues with your water pressure, you can opt for our pumped Reverse Osmosis with pump don't worry. Just call us on 020 8761 6611 (or +44 20 8761 6611 if outside the UK).

Back to Technical Contents

Hot Water / Temperatures

The Unit Must NOT BE FROZEN.

The Unit is NOT designed to filter HOT water. It should only filter water at ambient temperature. (Feed temp = 4 to 29 degrees C).

However please note that our Reverse Osmosis units are often used to supply filtered water to hot/boiling water taps and other systems where the temperature is changed. That is fine. But the system itself should not filter hot water.

Back to Technical Contents

What are the Materials Inside the Reverse Osmosis Tanks?

Some people are concerned about the materials the RO tanks are made from and how it might impact their purified water.

This is understandable:

Who wants to filter their water carefully only for it to be somehow polluted in the storage vessel while waiting to be used!

(Just to be clear: RO filtration is a highly effective but slow process. Rather than you waiting for the filter to produce enough water for you, the system purifies the water slowly and fills up the storage vessel / tank. When you turn on the RO drinking tap there's several litres of filtered water waiting for you. The system then refills the tank with whatever you took out).

Our RO tanks / storage vessels are made from highly durable steel. The water doesn't touch this - which is a good thing or the highly purified water could cause the metal to release chromium oxide into the water!

Instead, the water is stored inside an airtight rubber bladder / diaphragm.

This is made from "butyl rubber" which is lined with polypropylene - a commonly used food grade plastic (see "Hazard data" below).

All these materials are industry standard. We have never come across and other type of materials for Reverse Osmosis storage tanks - and, collectively, we've been in water filtration for over 50 years.

(Bear in mind that after leaving the tank the water is purified even further by the post filters).

Polypropylene Hazard Data:

No negative health effects and symptoms.

No negative physical and chemical effects.

No hazard for environment.

Sources: 1) ESIS European Chemical Substances Information
System: 2) Hazardous Substance Data Bank (HSDB) U.S.
National Library of Medicine, 2001-1

Back to Technical Contents

Changing the Cartridges

The four main filter cartridges need to be changed every six months (Cost £39.95).

We will send you a reminder every 6 months to change these filters.

6 Month Four Filter Pack Replacement Code: FRO-DM-UKWF

You can order a spare 6 month four filter pack here

The largest filter, the RO membrane has a life of approx 3 years (This depends on your local water quality) You'll know when a change is needed because of the obvious change in taste. We send you a reminder every three years.

Cost of replacement membrane is £9

Replacement Membrane Filter Code: MEM-RO

You can order a spare membrane filter here

Back to Technical Contents



With FREE Delivery

Immediate Dispatch

Purchase with Total Confidence

Money Back Guarantee

Click here for delivery information

No hidden extras

If you don't like what you get, send it back for a full no quibble refund.

If for any reason you decide to return your purchase we promise you a no questions asked THREE MONTH Money Back Guarantee. Click here to read the "large print" about our Money Back Guarantee.

PLUS We'll even pay your return postage !

Please order now to secure today's sale price.

Delivery & Returns

Free Second Class - up to 5 days (90% arrive in 3 days)

First Class - up to 2 days (95% next day delivery)

Free Returns and Money Back Guarantee. Full details

Free Lifetime Support

If you have any problems

... or concerns with your purchase we are here to help.

We are not "here today gone tomorrow" merchants.

A quick look at our Customer Feedback

... and our Money Back Guarantee should help reassure you that we are an honest firm who will give you a first class, long term service.

How to get help

Call our help line on 020 8761 6611 at any time during UK office hours ie 9 am to 6 pm

Or email us for a rapid response.

Our policy is always to get back to you within an hour - or one working day at most.


In addition to your 3 Year Warranty, if for any reason you change your mind about your purchase within 90 days of receiving the goods, you can return your product for a full and complete refund *

PLUS we will pay for your return postage (UK only)

*This applies to individuals/ consumers using the products in domestic settings. Businesses please see our terms and conditions

Delivery Times

Order before 3 pm on any working day and we guarantee your order will be sent out the same day (not on weekends)

(To be honest we often manage to send them even after 3pm. But we can't promise that).

All prices on the website include delivery charges and VAT except where stated otherwise.

Delivery Charges

Your Standard "Free Delivery Included" is Second Class

This usually takes between 3 to 5 working days ie does not count weekends or Bank Holidays

Pay Extra for First Class

You also have the option at checkout to pay extra for First Class.

This should result in next day working delivery to mainland UK.

BUT please note while 95% do arrive next day this is not guaranteed.

However arrival within two working days is almost certain.

You can see your delivery costs at the checkout stage before you buy.


Over 30,000+ happy customers

The great majority keep coming back for years because they like our friendly, helpful service and great value prices.

Free Delivery & Returns

All Orders Shipped Same Day Before 3pm

3 Year Full Parts Warranty