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Reverse Osmosis Water Filter System

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

Reverse Osmosis Water Filter System

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

More about your Reverse Osmosis Water Filter 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

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Our Usual Price
$524.00 INC VAT
Only 182 in stock at this price | Available for next day delivery
guaranteed-fit
UK Water Filters Promise

If you change your mind about your purchase, you can return it for free, within 90 days, for a full refund.

Add Extra Replacement Cartridges

UKWF Reverse Osmosis Cartridge Renewal with Remineraliser

UKWF Reverse Osmosis Cartridge Renewal with Remineraliser

$56.00
$56.00
MEM-RO Reverse Osmosis Membrane Replacement

MEM-RO Reverse Osmosis Membrane Replacement

$110.00
$110.00
Free Delivery & Returns
Order before 3pm for same day dispatch today
"Absolutely outstanding. The kit is superb, water tastes wonderful. Such lovely staff, always so helpful and easy to contact when you need advice. high quality service. 🤩 great work 🤩"
Kelly,  June

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Product Description

Bottled water quality. From £1.96 a week.

The Gold Standard. Extremely powerful purification: Removes 200+ contaminants — chlorine, fluoride, microplastics, heavy metals, pesticides, bacteria — then uniquely restores natural minerals so it tastes as good as it performs.

No plumber needed  ·  Easily install under your sink in an hour  ·  Everything included

Removes 200+ contaminants
Fluoride, lead, microplastics, pesticides, E.coli and more
Re-mineralised as standard
Restores natural minerals — better tasting than most RO systems
3-year warranty
Plus 90-day money-back guarantee & free returns
Same-day dispatch
Order before 4pm for same day despatch — free delivery included
Free lifetime support
UK-based team — we care! and always reply as soon as we can
31p a day to run
Less than a third the cost of a daily bottle of water. Reduce plastic waste!
£287 £378 Save £91 (24% off)
That's £1.96/week — inc. VAT & free delivery
100,000+ customers served 25+ years in business Trustpilot's best rated UK water filter company 

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. - verified buyer

If you want to remove the widest range of problem contaminants from your drinking water - like pesticides, bacteria (ecoli, cryptosporidium etc), 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.

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.

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

Why Our RO System Costs Much Less than Others

Without us having to cut corners

The honest answer has two parts.

First: we don't add filter stages you don't need.

Some suppliers market their RO systems by the number of "stages" — five-stage, seven-stage, even nine-stage.

More stages sounds more impressive.

But the filtration science doesn't support it.

A well-engineered RO system needs

  • a good pre-filter (we give you two),
  • the membrane
  • a remineraliser/ realkaliser filter
  • a post-filter (to polish the water before it reaches your tap.)

That's five stages.

Everything beyond that is either redundant, marginal in benefit, or added specifically to justify a higher price.

We know this because we've been in water filtration for over 25 years. We understand what each stage actually does — and doesn't do. So we build the system around the science, not around the price tag.  (More info here on unnecessary RO "stages")

Second: we sell direct, online only.

No showrooms, no sales reps visiting your home, no retail margins. Those costs don't make the water any cleaner, but they do make the unit considerably more expensive when other suppliers pass them on to you. We don't.

The result is a system that is, in our assessment, technically superior to many units sold at £400–£500 — at around half the price.

The 3-year warranty and 90-day money-back guarantee are there precisely because we're confident in that claim.


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 a less powerful but good undersink water filter.

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

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 - verified buyer

 

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

Why We Include a Re-Alkaliser as Standard

Reverse Osmosis is extraordinarily effective at removing contaminants — and that thoroughness has one side effect worth knowing about.

Natural tap water contains dissolved minerals, particularly calcium and magnesium bicarbonates. These act as a natural pH buffer, keeping water slightly alkaline (typically pH 7.5–8.5). When RO removes them, that buffering effect goes with them, and the filtered water becomes mildly acidic — typically in the pH 5.5–6.5 range.

This isn't dangerous, but mildly acidic water can taste flat or slightly sharp, and most water quality guidelines recommend drinking water that is neutral to mildly alkaline.

Our solution is simple: we re-add what RO removes.

Every system we supply includes a re-alkalising mineral media cartridge. As the purified water passes through it, natural minerals are reintroduced, raising the pH back to a neutral or mildly alkaline level — typically pH 7 to 8.

Most UK reverse osmosis suppliers don't include this. We do, as standard, at no extra cost.

(If for any reason you'd prefer the system without the re-alkaliser — for example, for a specific technical application — just let us know when ordering.)

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?

Here's the Honest Answer.

It's true that RO removes virtually everything from water — including calcium and magnesium, the naturally occurring minerals that give tap and spring water its characteristic taste and contribute modestly to your daily mineral intake.

Critics of RO sometimes present this as a serious health threat. The reality is more straightforward.

The actual concern — and why it doesn't apply to Reverse Osmosis

The scientific literature on demineralised water does suggest that drinking it exclusively over long periods, without dietary compensation, could marginally reduce mineral intake.

The more relevant mechanism is that very low-mineral water has a slightly greater capacity to leach minerals from foods during cooking.

Neither effect is dramatic — but they're real enough that the World Health Organisation recommends a minimum mineral content for drinking water, and real enough that we take them seriously.

Which is exactly why we include re-mineralising media as standard.

Before the purified water reaches your tap, it passes through a mineral restoration process that reintroduces calcium and magnesium at levels consistent with good-quality natural spring water.

You get the purity of RO with the mineral profile of bottled mineral water.

This is included in every system we sell, at no extra cost. Most UK RO suppliers don't do this.

What about minerals from food?

A balanced diet does provide the vast majority of your daily calcium and magnesium — your water contributes a relatively small fraction.

So even without our re-mineraliser, the risk from RO water alone would be modest for most healthy adults eating a reasonable diet. But modest is not zero, and there's no good reason to accept any unnecessary risk when the solution costs nothing extra.

So the reassuring facts are:

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

We do this with a 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. 

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. - verified buyer


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.

It comes with an easy-fit DIY self-tapping "saddle valve" that pierces your water pipe (works on 12mm and 15mm pipes - ie 99% of under sink pipes.

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 - verified buyer


Replacing the Filters

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


Cartridge Replacement Information


Replacement notes:

Your pre filter cartridges and membrane “drop in” to a housing. Tubing "push-fits" into your post filter cartridges. You replace the cartridges NOT the whole housings.
We send you a reminder when it’s time to change the cartridges.

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


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:

What you get — in plain numbers

200+
contaminants removed
99%+
filtration rate
12L
storage tank included
3 yr
full parts warranty
Filtration
Membrane type TFC (Thin Film Composite)
Rejection rate 98%+ dissolved solids
Filter stages 4 — no redundant stages
Re-mineraliser included Yes — as standard
System specs
Production rate 75 gallons/day
Tank capacity 12L nominal (5–9L usable)
Unit dimensions 43.5 × 35 × 12.5 cm
Feed pressure 2.7 – 6 bar
Running costs
Daily cost ~31p per day
Filter pack (×5) £39.95 every 6 months
Membrane £79 every 2–3 years
Peace of mind
Warranty 3 years (full parts)
Money-back guarantee 90 days, no questions
Installation DIY, ~1 hour, no plumber
  • 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 THREE MONTH Money Back Guarantee
  • Buy with complete confidence
  • Three year full parts warranty
  • Compact design
  • Failsafe flow restrictor
  • Auto shut-off/on full tank
  • Five top quality cartridges


ORDER ANYTIME Day or Night 24/7 for NEXT DAY DELIVERY

With FREE Delivery

Immediate Dispatch

Purchase with Total Confidence

THREE MONTH 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 !

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Product Code: RO-UKWF

Reverse Osmosis Kitchen water filter
Technical Information

Cartridge Replacement Information

  • Five filters needs to be replaced every: 6 Months.

  • Replacement code: FRO-DM-UKWF

  • The membrane filter needs replacing every 2 - 3 years on average *depending on local water conditions

  • Replacement code: MEM-RO

  • Running costs per day - approx: 31p

  • Replacement time / difficulty: Easy; takes a few minutes

  • Replacement notes:

    Your pre filter cartridges and membrane “drop in” to a housing. Tubing "push-fits" into your post filter cartridges. You replace the cartridges NOT the whole housings.
    We send you a reminder when it’s time to change the cartridges.

    Basic Tech Summary

    Dimensions

    How Much Water Does it Produce?

    List of Contaminants Removed by Reverse Osmosis

    Installing The System

    Replacing The Filters

    Is Your Water Pressure High Enough?

    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) 75 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). Size of hole to drill 12mm. Note marble, granite, quartz and other very hard worktops can be difficult to drill through. You will need a special diamond-tipped drill bit


    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 75 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 £79


    Replacement Membrane Filter Code: MEM-RO

    You can order a spare membrane filter here

    Back to Technical Contents

    Product CODE RO-UKWF / RO UKWF / ROUKWF

    ORDER ANYTIME Day or Night 24/7 for NEXT DAY DELIVERY

    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 !

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    SKU: RO-UKWFC
    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.

    Returns

    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.

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    We are a family run business who value our customers. We've been trading for over twenty five years. So we won't be "here today gone tomorrow". Your Money Back Guarantees and Warranties will be safe.

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    Members of Safebuy the leading Consumer Assurance Scheme for online retailers approved under the Trading Standards Institute's Consumer Codes Approval Scheme.

    Repeat Customers

    Many of our clients have been buying filters from us for several years. Over 95% keep coming back to renew their filter because we offer a friendly, helpful service and great value prices. Checkout our TrustPilot reviews.

    We’re Trustworthy

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