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Do you consume a great deal of drinking water in your household or wish to cook and fill your kettle with filtered water? If so, the Doulton Double Plastic Undersink Unit is ideal. It allows you to filter as much water as you require when you require it.
The Doulton Double Plastic Undersink Unit only requires basic level DIY. You may be able to fit it yourself. Otherwise, employing a plumber to do the job should be relatively inexpensive due to the nature of the installation.
See Videos tab (below) for installation video.
The Pre-Filter removes sediment like rust particles from your water prolonging the life of your main filter. A Pre-Filter is ideal if you don't have a problem with limescale or fluoride.
The Fluoride Filter will remove up to 75% of the fluoride from your water whether it is naturally occurring or added by your water company. Fluoride in your water has raised concerns about its effects on health and well being.
The Cleansoft Filter will reduce the limescale in your drinking water, helping to prevent the build-up of limescale on your taps and helping you enjoy a scum-free cup of tea!
The Ultracarb Filter has a broad filter capacity removing a variety of contaminants including bacteria, chlorine, cysts, heavy metal, particles and trace organics.If your tap water contains a high level of impurities, the Doulton Ultracarb Filter offers you peace of mind. It's ideal for great quality drinking and cooking water.
The Chlorasyl Filter has a broad filter capacity removing a variety of contaminants including chloramine, chlorine, cysts, bacteria, particles and trace organics.If your tap water contains a high level of impurities, the Doulton Chlorasyl Filter offers you peace of mind. It's ideal for great quality drinking and cooking water.
The filters have all been independently tested by NSF. This gives an extra assurance of the filter capacity of the Ultracarb filter and the quality of the manufacture of the product.
The Doulton Double Plastic Undersink Unit is compact and should fit comfortably in a standard undersink cupboard, out of the way. All the benefits without the intrusion!
|Water Filtration||Particles, Bacteria, Chloramine, Chlorine, Fluoride, Heavy Metals, Limescale Reduction, Organic Compounds|
|Filter Type(s)||5 micron Pre-Filter, Fluoride, Ultracarb, CleanSoft, Chlorasyl|
|Casing Material||FDA grade 100% Polypropylene|
|Flow Rate (l/min @ 3bar)||3.3|
|Flow Rate (l/min)||up to 4|
|Credentials||NSF Certified Components|
|Dimensions (mm) HxWxD||350 x 180 x 80|
|Warranty||1 year parts warranty|
Please download a user manual from the Manual tab for more technical and installation information.
For filter replacement periods please read the individual information tabs for the filters.
All our water filtration units can be installed with basic level DIY though many people prefer to use a qualified plumber. We suggest getting quotes from 3 different plumbers and showing them the fitting instructions.
Water filters must be fitted according to the manufacturer's instructions. Damage caused by plumbers inexperienced in fitting water filters cannot be covered by our guarantee. If the unit has to be returned to our supplier and damage has been caused a charge will be applied. All components are checked before despatch. Please check them carefully when they arrive. If any components have been damaged in transit please notify us immediately.
The Pre-filter cartridge takes the larger particles out protecting the ceramic Ultracarb filter or 5 Micron carbon block and helping to maintain flow rate and prolong the life of those main filters.
The Pre-filter should be replaced every six months. Do not use for longer than twelve months without replacing. Take a look at our Filter Replacement Service tab for peace of mind.
The Pre-filter cartridge is manufactured with ISO9001: 2000 Quality Assurance. NSF (National Sanitation Foundation), WRAS (Water Regulatory Advisory Scheme) and The Water Quality Association use a very strict set of criteria to continually monitor the filter candles and performance of the undersink units.
The Cleansoft lime scale reduction filter will reduce hardness in your drinking water and reduce the limescale build up on your taps and kettles. It will reduce the film that can form on the surface of your tea and other hot drinks.
The Cleansoft Filter should be replaced every six months. Do not use for longer than twelve months without replacing. Take a look at our Filter Replacement Service tab for peace of mind.
The fluoride reduction cartridge reduces unwanted naturally occurring and added fluoride to safe levels in your mains supplied drinking water. It will reduce fluoride by 50 to 75%.
The Fluoride Filter should be replaced every nine months. Do not use for longer than twelve months without replacing. Take a look at our Filter Replacement Service tab for peace of mind.
The Fluoride Filter is manufactured with ISO9001: 2000 Quality Assurance. WRAS (Water Regulatory Advisory Scheme) and The Water Quality Association use a very strict set of criteria to continually monitor the filter candles and performance of the undersink units.
Stage 1: Outer shell – Micro Filtration including pathogenic bacteria, cyst reduction and turbidity
Stage 2: Anti-bacterial formula within the ceramic matrix inhibits microbiological growth
Stage 3: Activated carbon block takes out chlorine and chloramine, improving taste and odour
Doulton® ceramic filter candles have an anti-bacterial matrix integrated into the ceramic mix, which inhibits bacterial growth on the filter.
Unique to Doulton® filter elements, a sealing mechanism that gives unrivalled microbiological protection.
Absolute(>99%) 0.9 micron
Nominal (>99.9%) 0.5 – 0.8 micron
Bacteria Removal E. Coli / Cholera / Shigella / Typhoid / Klebsiella Terrigena >99.99%
(including Giardia and live Cryptosporidium) >99.99%
Tested to 1000 US gallons (3800 litres) @ 0.5gpm >97%
Tested to 500 US gallons (1893 litres) @ 0.5gpm 95%
Tested to 700 US gallons (2650 litres) @ 0.3gpm 95%
US gallons @ 45 psi 0.5 GPM
Litres @ 3 Bar 1.9LPM
The first stage consists of Doulton Sterasyl® ceramic which provides genuine sub micron filtration. The cartridge reduces fine particulate matter, bacteria, cysts and turbidity. The incorporation of silver locked within the ceramic structure gives enhanced bacteriostatic and self steralising properties.
Pathogenic organisms removal
E. Coli - >99.99%
Vibrio Cholerae (Cholera) - >99.99%
Shigella - >99.99%
Salmonella Typhi (Typhoid) - >99.99%
Klebsiells Terrigen - >99.99%
Cryptosporidium - >99.99%
Giardia - >99.99%
The second stage - the inner core of the activated carbon block removes chlorine and organic compounds.
Free chlorine - > 97% - NSF Class 1 Std.42
Trace Organics Removal
One of the main properties of activated carbon is that it will remove organic compounds. Additionally the activated carbon in our filters has an affinity for hormone based steroids such as oestrogens so should help to remove them to some extent, testing is in it’s infancy so we are currently unable to make an accurate claim to the extent of the removal.
Lindane - >85%
TCP - >50%
PAH’s - >95%
Chloroform - >50%
The third stage - the ion exchange resin reduces lead and other heavy metals.
Lead - >98.3% - NSF Std. 53
The Ultracarb™ will remove other heavy metals such as copper and mercury but the amounts have not been quantified. The Ultracarb™ will not remove hardness from the water.
Replacing the filters
The Ultracarb™ filter should be replaced every six months for four people and every nine months for one to two people. Do not use for longer than twelve months without replacing. Take a look at our Filter Replacement Service tab for peace of mind.
Unrestricted flow at 3bar pressure will allow 3.3litres per minute. A flow of 1.9Litres offers maximum performance.
The Ultracarb™ filter is made up of Silver impregnated ceramic microfilter, activated carbon block, and ion exchange resin.
The Ultracarb™ is independently tested and accredited for your assurance of quality
The Ultracarb™ ceramic filter is manufactured with ISO9001: 2000 Quality Assurance. NSF (National Sanitation Foundation), WRAS (Water Regulatory Advisory Scheme) and The Water Quality Association use a very strict set of criteria to continually monitor the filter candles and performance of the undersink units.
NSF is an accredited organisation that independently develop standards, tests and certifies products and systems. Manufacturers, regulators and consumers look to NSF International for the development of public health standards and certification programs that help protect the world’s food, water, consumer products and environment. Their mission is to protect and improve global human health.
Once the flow coming out of the filter becomes noticeably less than normal.
Use a scouring pad (similar to 3M “Scotchbrite”). Ensure that the end of the plastic mount does not come into contact with unfiltered water and dirty hands. Rubber gloves are recommended to be used during cleaning and NEVER use soap or detergents!
In some water conditions, there is so much particulate or turbidity in the water supply that the filter element becomes blocked much more quickly than in normal conditions. In these circumstances, it is beneficial to use a pre‐filter upstream of the ceramic candle. This prevents the candle from becoming blocked too quickly, minimises cleaning and so extends the life of the ceramic filter.
This depends on the type of candle being used:
Sterasyl™ Should be replaced once cleaning fails to restore the water flow. However, we usually recommend that Sterasyl™ candles are replaced after 10,000 litres of water have passed through the candle, to guarantee optimum performance.
Super Sterasyl™, Supercarb™, and Ultracarb™ In combination filter elements (ceramic shells containing other types of filter media) cleaning the ceramic will not extend the life of the internal material. For example, the ‘life’ of the carbon block in Supercarb™ or Ultracarb™ filter elements is determined by the concentration of chlorine and/or volatile organic compounds in the water supply. The particulate and turbidity concentration in the water supply govern the life of the ceramic. This means that the life of the ceramic might or might not exceed the capacity of the carbon insert, depending on the water quality. Whichever point is reached first – the six months usage or the ceramic becoming blocked to the extent where cleaning does not restore the flow – governs when the filter element requires replacing. In most cases, the filter element should be replaced after 6 ‐12 months of daily use. The following flow guidelines can be used to guarantee optimum performance:
Super Sterasyl™ 2,000 litres or 535 US gallons
Supercarb™ 3,740 litres or 1000 US gallons
Ultracarb™ 2,244 litres or 600 US gallons
Once this amount of water has passed through the filter element, the filter will need to be replaced to guarantee optimum performance.
On average a family of four uses approximately 8 litres of water per day for cooking and drinking. Therefore, based on 10 litres/day for four people the life of your filter can be estimated in time rather than capacity.
The ceramic shell of Sterasyl™, Super Sterasyl™, Supercarb™, and Ultracarb™ filter elements all contain trace amounts of silver to prevent microbiological growth. These elements are self‐sterilising and should NOT be sterilised after cleaning. In the case of combination filter elements, boiling will damage the internal components of the element.
The filter housing is best cleaned by unscrewing the body from the head and wiping the surface and the inside of the body with a soft cloth dampened with warm water. IMPORTANT – DO NOT ATTEMPT TO CLEAN THE FILTER HEAD, WHICH COULD CAUSE CONTAMINATION OF THE FILTERED WATER.
If normal use of the filter is interrupted by holidays or time away from home, growth of harmless heterotrophic bacteria may result in a ‘flat’ or ‘stale’ taste for a period of time when use of the filter resumes. This is especially true for the filter elements that contain activated carbon such as the Super Sterasyl™ (contains granular activated carbon), the Supercarb™ and Ultracarb™ (both contain an extruded activated carbon core). Flushing the filter system for several minutes after any prolonged period of inactivity should eliminate the problem.
Hardness caused by the presence of positively charged metal ions. Total hardness is measured as the equivalent of milligrams per litre of calcium carbonate. Temporary hardness only contains metal carbonates and bicarbonates, the most typical being calcium carbonate. Temporary hardness is precipitated from water when heated and is responsible for the furring of heating elements and metal pipes. Permanent hardness consists of non‐carbonate based metal salts, and does not precipitate out on heating.
Unfortunately filtration does not remove hardness from water so Doulton® or British Berkefeld® filter elements will not affect the hardness in drinking water. Hardness can be removed by water softening, deionisation or magnetic and electrical conditioning devices.
The ATS media used in our Ultracarb™ filters will adsorb lead, even in the presence of calcium and magnesium ions. This is proven in the NSF certification testing. One of the test protocols for metal(s) reduction calls for testing at high pH, high TDS conditions to simulate use in hard waters. Filter elements containing ATS have to pass this part of the test protocol before they can receive NSF certification.
The Doulton® and British Berkefeld® range of ceramic water filters are only suitable for the removal of aluminium in particulate form. They are not proven to be suitable for treating dissolved aluminium. To treat water containing soluble aluminium, ion exchange resin, distillation or reverse osmosis must be used.
No, Arsenic is likely to be in a dissolved state, to remove arsenic passage through activated alumina is the best method.
No. The large number of different species of bacteria of different shape, size and growth characteristics, preclude the ceramic filter from being effective against all of them. The pathogenic bacteria that FICL claim to be effective against have been qualified by test data from independent test laboratories or are extrapolated from test data of similar microorganisms (please seek advice from FICL on permitted extrapolated claims). Although the ceramic will filter all types of heterotrophic bacteria to some extent, it should be noted that any harmless bacteria of this type passing through the ceramic may multiply downstream of the filter. Since these heterotrophic bacteria are harmless, normally there are no problems and some heterotrophic bacteria are reported to be beneficial to health. However, if normal use of the filter is interrupted by holidays or vacations, growth of these bacteria may result in a ‘flat' or ‘stale' taste for a period of time when use of the filter resumes. This is especially true for the filter elements that contain activated carbon such as the Super Sterasyl™ (contains granular activated carbon), the Supercarb™ and Ultracarb™ (both contain an extruded activated carbon core). Any system containing activated carbon, which will reduce residual levels of free chlorine, will result in an increase in plate counts over a short period of time until a constant state of equilibrium is established. The UK Drinking Water Inspectorate water regulations call for the water to be regularly monitored for consistency as used, therefore since an equilibrium point is reached in the filtered water, the filters comply with the regulations. The presence of this type of heterotrophic bacteria does not constitute a health problem since the organisms present will be harmless and a suitable level of consistency would be established. Flushing the filter system for several minutes after any prolonged period of inactivity should eliminate the problem.
Chloramine may be removed by passing through a bed of activated carbon, but requires much greater contact time with the carbon than chlorine, so a slow flow rate through the carbon must be ensured. Unfortunately although the Doulton® or British Berkefeld® Super Sterasyl™, Supercarb™, and Ultracarb™ filter elements contain activated carbon, they may reduce levels but will not remove chloramine because there is insufficient contact time with the carbon.
The ceramic part of our filter elements will not take out any of these organic materials. The activated carbon in the Supercarb™ and Ultracarb™ filter elements will have some effect. However, to remove these types of materials requires much greater quantities of activated carbon and much longer contact time than our filters can provide.
No. Fluoride salts are soluble in water. To remove dissolved fluoride, passage through activated alumina is the best method.
The Doulton® and British Berkefeld® ranges of ceramic water filters are only suitable for the removal of iron in particulate form. They are not proven as suitable for treating dissolved iron. To treat water containing soluble iron, the iron must be oxidised to induce precipitation prior to filtration. Alternatively distillation or reverse osmosis can be used.
Since Legionella has a similar morphology to E‐coli, our ceramic filter elements should provide similar protection against Legionella . However, Legionella is capable of slow regrowth downstream of the filter, so if just one organism passes through the ceramic it could eventually colonise the water delivery system. Therefore it is important to regularly disinfect downstream of the filter or fit a UV light just after the filter.
No, to remove Manganese, oxidation treatment and filtration can be done, or for low levels of contamination, Green sand or Inversand can be used.
Unfortunately the ceramic filter elements will not remove nitrates. In the home the only effective method that can be used to remove nitrates is ion exchange media.
There has been a limited amount of research into oestrogen and synthetic oestrogen, and so we do not have quantifiable test data on the effectiveness of our products in removing it. Due to the chemical properties of oestrogen, we believe that activated carbon would be effective in reducing it. However until better test methodology is available, we are unable make a claim.
Pseudomonas aeroginosa is a potential coloniser of water system networks and is similar in size to E‐coli. FICL candles should therefore, in theory, show a similar reduction efficiency for Pseudomonas aeroginosa as for E‐coli. However, since this organism is rapid growing and may recover quickly, without physically testing FICL ceramic filters with this type of organism, it is impossible to predict a performance claim. FICL is not prepared to attempt a prediction of performance, since the filters provide a <99.99% barrier, but do not provide 100% barrier to E‐coli. A limited number of cells may pass through the filter which, unlike E‐coli, may form colonies down stream of the filter. It would be more suitable to combine filtration with a disinfection stage to ensure removal of Pseudomonas aeroginosa.
The slight increase in the pH of water passed through the ceramic filters is due to the presence of the mineral Wollastonite in the ceramic. Wollastonite is slightly soluble and alkaline, so may partly dissolve in the water as it passes through the filter causing a minor pH shift which is harmless. No health based guideline value for pH in drinking water has been proposed by the WHO, although accompanying notes to the guidelines state that the pH range is often in the range of 6.5‐9.5. In general there is little evidence to suggest that pH in potable water of around 9‐10 is of public health significance.
In the absence of conclusive data regarding the levels of infective doses for specific pathogens, the FICL microbiological laboratory has been testing our filter elements for many years using an influent challenge of 6 log of E‐Coli to substantiate the 4 log E‐coli reduction claim that we make. This level of protection offered by the filters is more than adequate in all protected waters and the vast majority of moderately contaminated surface waters. However, if the level of contamination in the water exceeds levels of 104 (4log) an additional treatment must be used such as disinfection or UV light treatment. It would be extremely unusual for water having a greater level of contamination than 104, to be considered suitable as a potable water source.
British Berkefeld is an FICL trademark. Berkey is not an FICL trademark. FICL manufactures all British Berkefeld branded filter products. FICL manufactures some British Berkefeld branded Super Sterasyl grade ceramic filter candles which are used inside certain Berkey filter systems. FICL is not involved in the manufacture of Black Berkey filter elements or any other Berkey branded filter products.
Whether you purchase air purifiers, dehumidifiers or water filters, or any of their replacement parts we offer you peace of mind. We will add your name to our reminder service. In accordance with the manufacturers' guidelines we will send you a gentle reminder that your unit may need replacement parts. Maintaining its efficiency will continue providing you a healthier environment.
We will be able to supply you with your required replacements. We maintain stock levels of filters and cartridges even after a manufacturer may bring the original unit to an end. This means our customers can rest assured of our commitment to servicing their requirements long into the future.
If you do not wish to be included in our service then we can simply unsubscribe you. Similarly, if you have not purchased the units or replacements from us before you may ask to be included in our service for future use.
With best wishes
The Healthy House® Team
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