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 (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.

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). | ![]() |
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
Important Note about Acidic water
List of Contaminants Removed by Reverse Osmosis
What are Reverse Osmosis Stages?
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
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 !
Please order now to secure today’s sale price.

Product Code: RO-UKWF