Paints & DIY
Doulton® water filters have now been manufactured continuously in the UK for more than 185 years. In the 19th Century, the River Thames was London’s main water supply.... and sewer. Henry Doulton discovered the benefits of filtered water. He found that filtering water through a porous ceramic could stop people becoming sick. Sickness such as cholera and other water-borne diseases could become a thing of the past. Queen Victoria was an early and long-standing Doulton® customer!
Fairey Industrial Ceramics Limited (FICL) is the sole manufacturer of the world famous range of Doulton® ceramic drinking water filters. All Doulton® ceramic water filter products are manufactured in FICL’s factory. It is based in North Staffordshire, UK, the traditional home of the ceramic industry in England.
Doulton pride themselves on being of the highest quality, leading the way in filtered drinking water standards. All stages of the Doulton® drinking water filter production process adhere to the stringent BS EN ISO 9001 quality standards. The company holds the coveted NSF® and WRAS certificates. This demonstrates their drinking water filters have passed the highest testing standards.
For further information and answered questions read our Doulton Filters F.A.Q.s below....
How do I know when my ceramic filter element needs cleaning?
This can vary depending on usage and water quality, but the best indication is when the water flow becomes noticeably less than normal. This reduction in flow is due to contaminants blocking the water pathway and proves that the ceramic element is successfully filtering out foreign bodies. Another consideration is the colour. When new, the colour of the ceramic filter is white; any dis-colourment during use is due to contaminants being filtered out. For optimum performance, clean as explained in the question below.
How do I clean a ceramic filter candle?
We recommend a gentle buffeting with a scouring pad until the whiteness of the ceramic returns. Heavy rubbing or over abrasive material may remove more of the ceramic than is actually necessary. Rubber gloves are recommended to be used during cleaning and NEVER use soap or detergents. Ensure that the end of the plastic mount does not come into contact with unfiltered water.
Why is my ceramic filter element discoloured?
This is physical proof that it has been successfully filtering out contaminants which in most cases are invisible to the naked eye. The micro porous properties of the ceramic will remove contaminates which would have otherwise passed undetected for consumption. The colour of the candle will vary depending on what contaminants are evident in the water supply. The candle will return to its ceramic white by following the simple cleaning steps as explained above.
I don’t have a flow meter to gauge the amount of water that my filter has treated. How can I estimate how much water has passed through the filter?
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.
My ceramic filter seems to block up too regularly; is it working correctly?
Yes, regular blocking may be simply due to the turbidity or particles in the water supply. This proves that the filter is working efficiently; it is the ceramic filtering out contaminants and therefore reducing the water flow, but it may be beneficial to use a pre-filter upstream of the ceramic filter. This prevents the candle from becoming blocked too quickly; it minimises cleaning and therefore extends the life of the ceramic filter.
For optimum performance, when should a ceramic candle be replaced?
This depends on frequency of use, water quality and the grade of ceramic candle in your system. The following guideline for replacing the various ceramic grades:
Should be replaced once cleaning fails to restore the water flow. However, we usually recommend that Sterasyl® candles are replaced after 12 months or 10,000 litres (2,600 US gallons) of water have passed through the candle, to guarantee optimum performance.
Super Sterasyl®, Supercarb®, Chlorasyl® 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®, Chlorasyl® or Ultracarb® filter elements is determined by the concentration of chlorine and/or chloramine 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® 3,800 litres or 1000 US gallons
Chlorasyl® 3,800 litres or 1000 US gallons based on free chlorine removal
Ultracarb® 2,300 litres or 600 US gallons
After this amount of water has passed through the filter element, the filter will need to be replaced to guarantee optimum performance.
Do I need to sterilise the candle after cleaning?
No, there is no need to sterilise the ceramic candle. Sterasyl®, Super Sterasyl®, Supercarb®, Chlorasyl® and Ultracarb® all have the benefit of containing trace elements of silver locked into the ceramic matrix. This prevents microbiological growth and removes the need for sterilisation.
How do I keep my filter housing clean?
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. It is important not to attempt to clean the filter head. This could cause contamination of the filtered water.
What happens if I leave the filter unused for a period of time?
Due to self sterilising, our ceramic candles will not be harmed by lack of use for a period of time. If normal use of the filter is interrupted by holidays or vacations, 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®, Chlorasyl® 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.
How effective is my Doulton® or British Berkefeld® filter element against Chloramine?
The Chlorasyl® grade of ceramic filter has an activated carbon block insert which takes out chlorine and monochloramine, improving the taste and odour of drinking water.
What is the difference between temporary and permanent hardness in water?
Hardness is 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.
How effective is my Doulton® or British Berkefeld® filter element against hardness?
The ceramic candle will not remove hardness in water, but our CleanSoft™ cartridge will. It contains an ion exchange resin which reduces temporary hardness in water. This helps to prevent limescale build up on kettles and unpleasant film forming on hot drinks (particularly tea). The CleanSoft™ cartridge is supplied with our DUO system as a stage 1 filtration unit. The DUO™ has the benefit of a 2ndstage filter to include either Supercarb®, Chlorasyl® or Ultracarb®.
Will hardness affect the performance of an Ultracarb® filter element?
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 (Total Dissolved Solids) 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.
How effective is my Doulton® or British Berkefeld® filter element against Aluminium?
The Doulton® and British Berkefeld® range of ceramic water filters are only suitable for the removal of aluminium in particulate form. >99.99% will be removed at 0.9 micron or >99.9% at 0.5 to 0.8 micron. 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.
How effective is my Doulton® or British Berkefeld® filter element against Arsenic?
Unfortuantely filtration does not remove Arsenic from water. Arsenic is likely to be in a dissolved state, to remove arsenic passage through activated alumina is the best method.
How effective is my Doulton® or British Berkefeld® against all types of bacteria?
Due to the vast number of different species of bacteria which vary in shape, size and growth characteristics, it would be impossible for the ceramic filter to be effective against each type. However, Doulton® and British Berkefeld® ceramic filters are successful in removing the most prevalent and harmful species, Pathogenic Bacteria.
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®, Chlorasyl® 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.
How effective is my Doulton® or British Berkefeld® filter element against diesel, petroleum or MTBE?
The ceramic part of our filter elements will not take out any of these organic materials. The activated carbon in the Supercarb®, Chlorasyl® 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.
How effective is my Doulton® or British Berkefeld® filter element against Fluoride?
The ceramic candle will not remove Fluoride, but our Fluoride reduction cartridge will. This cartridge is constructed with WRAS and NSF approved materials and is compatible with the under-counter and counter-top range of housings. It can also be used in our DUO™ system as a stage 1 filtration. The DUO™ has the benefit of a 2nd stage filter to include either Supercarb®, Cholorasyl® or Ultracarb®.
How effective is my Doulton® or British Berkefeld® filter element against Iron?
The Doulton® and British Berkefeld® ranges of ceramic water filters are only suitable for the removal of iron in particulate form. >99.99% will be removed at 0.9 micron or >99.9% at 0.5 to 0.8 micron. 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.
How effective is my Doulton® or British Berkefeld® filter element against Legionella?
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.
How effective is my Doulton® or British Berkefeld® filter element against Manganese?
Manganese will not be removed by the ceramic filter element. To remove Manganese, oxidation treatment and filtration can be done, or for low levels of contamination, Green sand or Inversand can be used.
How effective is my Doulton® or British Berkefeld® filter element against Nitrates?
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.
How effective is my Doulton® or British Berkefeld® filter element against Oestrogen and Synthetic Oestrogen?
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.
How effective is my Doulton® or British Berkefeld® filter element against Pseudomonas aeroginosa?
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.
Why does the pH of my drinking water increase when I use my ceramic filter?
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.
What level of bacterial contamination can the ceramic cope with before I need to use something else?
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.
Does FICL manufacture the Berkey filter range including the Black Berkey filter element?
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.
Do all ceramic candles available in the market achieve the same contaminate removal rate?
No, we can only vouch for the quality and removal claims of the British Berkefeld® and Doulton® ceramic candles. We are a UK ISO accredited company whose manufacturing processes and methods are strictly monitored. We also have our products independently and regularly tested to prove that they meet the specifications, we claim.
Is my ceramic filter element ecologically friendly?
Yes, British Berkefeld® and Doulton® ceramic candles are produced from 100% natural materials and can be disposed of safely in land fill.