Finerfilters 6 Stage Domestic Reverse Osmosis Under Sink System With Fluoride Removal (50 GPD)

Finerfilters 6 Stage Domestic Reverse Osmosis Under Sink System With Fluoride Removal (50 GPD)

Product ID: FF-RO-SYST-D6

Availability: In stock

£99.99 inc. VAT

Finerfilters 6 Stage Domestic 
Under Sink Reverse Osmosis System

Reverse Osmosis is a technology that is used to remove the large majority (98%+) of contaminants from water. The Reverse Osmosis system works by pushing the water under pressure through a number of increasingly smaller filters and finally through a semipermeable membrane, essentially trapping all contaminants.

Finerfilters are here to support you before and long after you buy. We provide help through manuals, easy install guides, diagrams, phone & email support.

This system produces up to 190 litres per day of purified water and comes complete with:

A 3 US gallon pressurised storage tank holding 6.5 litres of RO filtered water.

Installation Manual.

Chrome Faucet Tap.

All pipes, pre-filters, post filters, and fittings required for easy Installation.

The membrane can last between 1 and 2 years dependent on water hardness. Filters to be replaced every six months.

Please note: 

This system requires a minimum of 45 PSI (3 BAR) to work.

Ideal pressure depends upon incoming water temperature but around 60 PSI (4 BAR) is acceptable.

If you have lower pressure you will likely require a booster pump or pumped RO system which can found by following these links or in the "You may also like" section below.

Diaphragm Booster Pump

Diaphragm Boost Pump & Upgrade Kit

5 Stage Pumped Reverse Osmosis System

6 Stage Pumped Reverse Osmosis System

Reverse Osmosis Systems waste water to make water, and this should be done at a high pressure as the water is being forced through microscopic holes which catches contaminants. 

This is normal and the same with all RO systems as this is the way the membrane rejects the impure water, which goes to the drain, to produce the pure water.

The system works optimally at 80-90 PSI (5.5 – 6 bar), and to get to the quoted output, we’d recommend running the system on or around this pressure.

This allows the system to reduce the waste water to pure water ratio and work quicker at producing pure water.

As many people won’t have this mains pressure; pumped RO Systems or booster pumps can be purchased from us and added to the system which will increase the pressure output (a minimum of 29 PSI (2 bar) is required to operate the booster pump).
Please ensure your mains water pressure meets or exceeds this before purchasing.

Product Detail


Finerfilters Domestic Undersink 6 Stage Reverse Osmosis System (50 GPD)

The 6 stages of filtration are;

Stage 1

A 5 Micron Sediment Filter Made of 100% Pure Polypropylene Fibres. Removes Dirt, Sand and Rust.

Stage 2

A Granular Activated Carbon Filter Composed of High - Performance Activated Carbon. Removes Free Chlorine, Odour, Organic Contaminants, Pesticides and Chemicals.

Stage 3

A Carbon Block Filter Composed of High Performance Carbon. Removes Trihalomethanes, Pesticides, Volatile Organic Chemicals and 99.95% of Giardia and Cryptosporidium Cysts.

Stage 4

A High Rejection Thin Film Composite 50 GPD Reverse Osmosis Membrane with the Capacity to Produce up to 190 Litres of Purified Water per day. This Membrane Removes Contaminants Present in Water Including, up to 99% of Dissolved Salts, Lead, Copper, Barium, Bacterial By-Products, Oestrogen and Silica.

Stage 5

A Post Carbon Filter Designed to Improve Taste. It Removes any Residual Impurities and Odours from the Tank and Provides a Finer Conditioning of the Purified Water.

Stage 6

Remineralizing filter to enrich the water ions with health essential minerals including: Calcium, Magnesium, Potassium and Sodium.

Plastic Water Storage Tank

Made of food grade reinforced Polypropylene.

Contains a food grade Butyl diaphragm/bladder which holds the water, ensuring tasteless, odourless & contaminant free water.

This tank is an air bladder tank meaning the water does not touch the metal outer shell, but rests in a Butyl bladder. There is a small air charge between the outside of the bladder and the inside of the tank. It’s this air pressure that pushes the water out of the tank when the tap is opened.

The tank is pre-charged with air but will require topping up as part of the regular maintenance of your reverse osmosis system. Air can be added using a bicycle pump or similar.


This tank can be connected to additional tanks to increase the storage capacity on your Reverse Osmosis system.
Tank uses ¼” Female x ¼” Pushfit Angled Shut Off Valve.
Plastic tank holds 6.5 litres of water.

Working Pressure: 50 PSI

Bottom Air Charge Pressure: 5-7 PSI

Dimensions: 36cm x 25cm x 25cm

System Measurements

6 Stage Reverse Osmosis System (No Pump)

Length 45cm
Width 26cm
Height 44cm
Weight 13kg

Approximate percentage (%) of contaminants removed by Reverse Osmosis.

Aluminium: 96 - 98

Lead: 95 - 98

Ammonium: 80 - 90

Magnesium: 93 - 98

Bacteria: 99+

Manganese: 96 - 98

Boron: 50 - 70

Mercury: 94 - 98

Bromide: 90 - 95

Nickel: 96 - 98

Cadmium: 93 - 97

Nitrate: 97 - 99

Calcium: 93 - 98

Phosphate: 95 - 98

Chlorine: 98+

Potassium: 92 - 96

Chloride: 92 - 95

Silica: 80 - 90

Chromate: 85 - 95

Silicate: 92 - 95

Copper: 96 - 98

Silver: 93 - 96

Cyanide: 85 - 95

Sodium: 92 - 98

Fluoride: 95 - 98

Sulphate: 96 - 98

Hardness: 93 - 97

Thiosulphate: 96 - 98

Iron: 96 - 98

Zinc: 96 - 98



3 Item(s)

3 Review(s)
23 December 2019
Truly good product
I genuinely wasn't sure whether the FinerFilter product was any good on account of how cheap it is and whenever you look at reviews you never know whether they're genuine or not, especially the positive ones. Well I have researched extensively and I am not sure what other brands may offer as it was my first time purchasing a reverse osmosis filter but this has been brilliant. The water is truly purified and the coconut filter makes it taste great, much better than any bottled brand and my wife is really fussy about the taste of her water. I really don't see why anybody would spend money on an unreasonably expensive product when this performs so well. I have had it installed several months ago ( I think about 4 and it's still going strong. The replacements are reasonably priced. Plus, I have absolutely no plumbing or general DIY experience however after several failed attempts to book a plumber to do it I was able to get the job done by myself using the video that finerfilters has online. The video could use with an update as it explains fitting for a slightly different model and it can be confusing for the utter clueless like myself but it was sufficient for me to be able to install it. The only bit I need to mention is the tank that you buy with the reverse osmosis filter, despite being a 10l tank I can only get about 3 litres of pressure out of it before I have to wait for the pump ( I had to buy a pump because the water pressure in my house was below the minimum threshold for the Reverse Osmosis membrane to work) to kick in and restore the pressure necessary for the water to flow again at a decent rate. Perhaps I am doing something wrong and that may be the reason why this happens I have not yet tried to contact customer service regarding this matter so I can check whether this is how it is intended to work under these circumstances Regardless of that minor inconvenience which may be due to my inability to set it up properly, for the reasonable price it costs I highly recommend this product, that is why I took the time to review it about 6 months after I bought it and 4 months after I had it fitted.
19 November 2019
Couldn't recommend this system and FinerFilters enough. Their customer support is wonderful, and the product is excellent and extremely well priced. I did a lot of research before ending up here with this product, but I'm very happy I did.
3 July 2017
Excelent After sale Costumer Service
Hi I wanted to thank you for your service after sale. The return of my purchase and receiving my new order was very easy, and Shane in particular was supper helpful in getting the change over of returned item swift and hassle free. My experience with your company have taken away my fear of on line shopping. Thanks you Shane. Fibi Wimbledon.
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