Doulton Ceramic Water Filters

Doulton Ceramic Water Filters are definitely the finest quality, and have unique materials, with the greatest capacity to remove all of the bacteria. That’s quite exceptional for a filter of this size and cost. For example they will remove 99.99% of the following bacteria:

E.Coli,   Vibrio Cholerae,   Shigella,   Salmonella Typhi,   Klebsiella Terrigena.

They also remove 99.99% of cysts such as Cryptosporidium and Giardia as well as 98.3% of lead, 97% of chlorine, 95% of Hydrocarbons, up to 85% of insecticides, herbicides, etc. Their depth filtration of particulate .2 micron help remove dirt, asbestos etc.

And also they give outstanding improvement in Taste and Odor.

The ceramic cartridges are NSF Certified and are manufactured in accordance with BS EN ISO 9002 quality assurance procedures.

For further information about the special ceramic shell (Bacteriostatic) and specialized carbon core click here.

For a company that’s been around for over 150 years and whose products are used in over 130 countries (government and relief agencies), Doulton has passed the test of time and quality.

Please read the history as proof of the quality of this excellent product.

At the heart of every Doulton water filter candle is a ‘Sterasyl’ silver impregnated ceramic microfilter. Fairey Industrial Ceramics is the worlds leading manufacturer of ceramic materials with closely controlled pore sizes. This expertise gives Doulton candles the highly consistent and controlled pore structure necessary to remove a wide range of water borne contaminants over the life of the filter. The incorporation of silver locked within the ceramic structure, gives each candle enhanced bacteriostatic properties. Silver inhibits the growth of bacteria giving the candles self sterilising properties and removes the need for regular boiling. By incorportaing activated carbon in the form of a fine coating, granular carbon or carbon block, the sterasyl ceramic can also be produced in Super Sterasyl, Carbosyl, and Supercarb grades which combine the advantages of ceramic and carbon filtration within a single filter element. At the top end of the product range the Ultracarb candle has an additional ion exchange media which reduces Lead and other harmful heavy metals.
Candle Grade Sterasyl Silver impregnated ceramic microfilter Super Sterasyl Streasyl microfilter plus Granular activated carbon
FILTRATION RATING (% particulate filtration efficiency) Absolute (defined as >99.99%) 0.9 micron 0.9 micron
Nominal (defined as >99.9%) 0.5 to 0.8 micron 0.5 to 0.8 micron
WORKING PRESSURE (for pressure filter use) Minimum 10p.s.i. 10p.s.i.
Maximum 125p.s.i. 125p.s.i.
WORKING PRARMETERS Working Temperature range 5-38 (°C) 5-38 (°C)
Working ph range 5.5-9.5 5.5-9.5
Suitable for use in gravity filters Yes Yes
Reccommended change frequency 12 months 6 months
FLOW RATE Unrestricted flow at 3 bar pressure Litres per minute 4 4.5
US gallons per minute 1.05 1.2
To achieve maximum performance Litres per minute N/A 1.5
US gallons per minute N/A 0.4
CAPACITY Before replacement to guarantee performance Litres 10,000 2,000
US gallons 2,600 535
QUALITY APPROVALS NSF Approved version available Yes No
WRc Approved Yes Yes
NSF Turbidity Reduction std. 53 >99.69% >99.69%
PATHOGENIC ORGANISMS % Bacteria Removed E.Coli >99.99% >99.99%
Vibrio Cholerae (Cholera) >99.99% >99.99%
Shigella >99.999% >99.999%
Salmonella Typhi (Typhoid) >99.999% >99.999%
Klebsiella Terrigena >99.99% >99.99%
% Cyst Removal Cryptosporidium >99.999% >99.999%
Giardia >99.999% >99.999%
TRACE ORGANICS REMOVAL Insecticides Lindane @ 0.1 ppb presence N/A No Data
Herbicides Atrizine @ 1.2 ppb presence N/A No Data
Phenols TCP @ 150 ppb presence N/A No Data
Polyaromatic Hydrocarbons PAH’s @ 0.2 ppb presence N/A No Data
Trihalomethanes Chloroform @ 150 ppb presence N/A No Data
INORGANICS REMOVAL Free Chlorine Removal 2mg cl/l challenge N/A Under gravity >95% Under pressure >50%
Lead Removal @pH 6.5 after 2,244 ltrs N/A N/A
@pH 8.5 after 2,244ltrs N/A N/A

Doulton – World Class 3 Stage Ceramic Water Filter Candle

History In 1835 Queen Victoria recognized the health dangers in drinking water and commissioned Doulton to produce a drinking water filter for the Royal household. By 1901 Henry Doulton had been knighted, and his company honoured by authorizing it to use the word ROYAL in reference to its products. The efficiency of domestic Doulton water filters has been widely extended over the years to meet the demands of increasingly sophisticated uses. Doulton ceramic water filters are now in use in over 150 countries.

A Closer Look Inside


Doulton ceramic is made from Kieselguhr Diatomaceous Earth and fired to above 1000 degrees Celsius. Over 80,000 overlapping pores make up each element. This feature provides absolute mechanical filtration to .9 of a micron. 99.999% rejection of bacteria and cysts. Bacteria and any other foreign particles as small as .2 of a micron are trapped on the outside of the element while the water passes through the ceramic wall to the inside of the element. Doulton ceramic candles are rigorously tested and fully certified.


This simply means self sterilizing. The entire ceramic wall is impregnated with oligodynamic silver. Silver has been long proven as a disinfectant which insures that bacteria trapped in the ceramic’s pores are killed thereby eliminating any threat of bacteria colonization.


Inside the Ceramic shell is a post filter which is manufactured by combining a zeolite metal ion reduction medium, granular carbon and powdered carbon to form a tightly packed matrix. This post filter provides two key features; Chemical Reduction (chlorine, pesticides, solvents, etc.) and Heavy Metal Reduction (lead, iron, aluminium, etc.) Medical authorities are now identifying heavy metals as key players in the degradation of mental health in humans. Follow the above links to see why you would want to remove these substances.

Key Features

ELIMINATES BACTERIA – Cholera, Typhoid, Salmonella, Serratia, E. Coli, Fecal Coliform, Etc.

Eliminates Cryptosporidium Parvum and Gardia Lambia Cysts (Beaver Fever)

Sub-Micron Particulate Filtration

Quickly and Easily Cleaned for Prolonged Life and Outstanding Economics

Self Sterilization Bacteriostatic

Cannot “Plug Up” Internally

No Tools Required to Service

Doulton holds Certification, Accreditation, or Membership with the following Agencies:

ISO 9002 Quality Standard
National Sanitation Foundation standards 42 and 53
Environmental Protection Agency (EPA)
Water Quality Association
Department of Health (Toronto, Canada)
Spectrum Labs (Minneapolis, USA)
Water Research Council (UK)
British 5750 Quality Standard
England’s Water Research council (WRc) Performance Standards
California Department of Health
Over 50 Independent Laboratories Worldwide

Single Element – Counter Top Model

This elegant inexpensive counter top model attaches to your existing kitchen faucet in seconds. Excellent for residents where permanent installation is not desired. This unit’s ease of mobility also makes it ideally suited for cottage and RV owners. Adapters are available to ensure compatibility with everything from traditional faucet designs to your common garden hose.

Single Element – Under Counter model

Designed for permanent installation this model comes complete with its own faucet and installation hardware. A No Tools to Service design makes this system simple to maintain. With the addition of extra hose, your fridge, ice machine, wet bar and even your humidifier can all be dispensing quality water from just one installation site.

Beyond Filtration

PakWater Care Services Stage Four and More ……

The Doulton ceramic element is an excellent beginning for improving your drinking water, but with the addition of PWC’s specialized cartridges you can economically turn your filtration system into a customized purification system. Additional stages can tackle problems such as excessive heavy metals, strong odors, elevated chemical content, nitrates and even fluoride reduction. The addition of one or more specialty cartridges will dramatically increase the removal efficiency of your entire system.

Multi-Element Systems

additional housings are simply “plugged in”, one behind the other. They may be added at any time. These additional cartridges do not require cleaning. They are simply disposed of at the end of their rated life.


The pore structure of the ceramic element is designed to trap fine particles and bacteria. In doing so, the outside of the element will eventually require cleaning. The need for cleaning becomes evident as the water flow from the drinking faucet becomes reduced. When this occurs, remove the element and give it a light scrub under running water. This will restore the original flow of water. If it does not then this is a sign that the element is due for replacement.


Counter top models:

These require only the removal of the air diffuser from your existing kitchen faucet. The diverter valve, which is already fitted to the supply hose, is then threaded onto the faucet and the installation is complete.

Doulton Water Filter Ceramic Candle & Cartridge Technologies, taking the mysteries out of the drinking water filtration

Ceramics, a natural water filter – Sterasyl micro-filter

Doulton mines only the finest and purest kieselguhr or diatom earth often described as a silica-like sediment resulting from kiesel algae (one celled algae) deposited on the bottom of geological lakes and lagoons millions of years ago. This is the same material used in making the finest bone china (like of Royal Doulton) and numerous other applications.

The filter elements are produced using the latest ceramic techniques to provide a hollow porous ceramic which is fired at a temperature in excess of 1000°C. The chemically inert ceramic filter can be stored for eternity without losing its effectiveness.

Doulton ceramic filter particles from the water but leaves oxygen and mineral contents unchanged, which gives water it’s spring-like freshness and taste (not “pure” but wholesome). Pathogens of the most varied diseases which are reliably filtered from the water include; cholera, typhus, cryptosporidium, amoebic dysentery, ecoli, colibacillose or bilharzia, anthrax spores among others.

Ceramic filtration technology is often called “dead-end filtration” and “depth filtration”.

There are several mechanisms by which the ceramic element filters out particles as a dead-end filtration.
a) Direct interception or sieving (fig. 1): Particle of 0.5 µm and larger “runs into” a pore that is smaller than the particle of topmost layer of the ceramic and are captured as with absolute pore rated synthetic dead-end membranes.

b) Bridging (fig. 2): Smaller than 0.5 µm particles may be too small to be intercepted however two particles hitting the obstruction at the same time will form a bridge across the pore adhering to each other. Bridged particles may not plug the pore creating even smaller pore gradually forming a “filter cake”. This “cake” creates a finer filtration for subsequent interception at the cost of decreased flow rate and eventually no flow rate.

Mechanical regeneration of the filter “cake” is simple. The topmost blocked layer can be removed with stiff brush or nylon scouring pad. This can be repeated many times before the filter has to be changed.

c) Inertial impaction (fig. 3): Particles flowing through the filter hits none porous surface barrier it become captured while the water flows around the barrier. Inertial impaction is more prevalent with smaller particles in range of 0.1 to 0.4 µm size as these particles are easily affected by molecular bombardment.

Unlike with synthetic membranes, all of the above methods of capture are dependable under variable operating conditions e.g. pressure surging, pulsing etc. with Doulton ceramics.

Ceramic depth filtration will filter out considerably smaller particles than equivalent pore size membrane for the following reasons:

a) Particles intercepted within the ceramic depth are much smaller than the pores measured by porometry. This is because particle laden water has to navigate through intricate maze of labyrinths. The path through the filter twists and turns trough sharp angles due to complicated ceramic structure and so the particles that may have penetrated the topmost layer become trapped within the structure.

To appreciate the distance and how difficult a path the water has to follow, consider that the wall thickness of the ceramic is 1000-2000 times greater than the pore size of the ceramic filter and the pores are sharp and jagged rather than smooth and round.

b) Small particles can combine with other particles to form a cluster of particles large enough to become trapped as a group or individual in dead end cavities.

c) Weak Van der Waals forces (adsorption fig. 4) attract the small particles to the ceramic, causing them to be adsorbed onto the wall of the ceramic. Depth filtration is very dependable as pressure surges are not affecting adsorption because the pressure is stabilized (drops by 50%) on the surface of the ceramic. Doulton ceramic depth filtration captures particles as small as 0.05 µm with greater than 90% efficiency.

Given favourable conditions, the accumulated bacteria could proliferate and grow unless prevented by some means.

To prevent this Doulton elements (except the Standard, Ceracarb and Ceramet) are manufactured with a small amount (about 0.07%) of pure silver (Ag) through-out the porous ceramic shell. Silver is a recognized bactericide, so when the bacteria comes into contact with the silver impregnated ceramic, their growth is inhibited. This self-sterilizing effect is known as the bacteriostatic effect.

Free silver ions (Ag+) have a toxic effect on micro-organisms even in relatively low concentrations. They have a highly fungicidal, bactericidal and algaecidel effect. Medical studies describe silver ions a catalyst that disable the enzymes that microorganisms depend on to “breathe”.

In the presence of air (oxygen in water), metallic silver forms silver oxide, which also has a bactericidal effect due to its adequate solubility. The destruction of viruses, bacteria, moulds, spores and fungi through contact with silver objects is termed the oligodynamic effect. To primitive life forms, oligodynamic silver is as toxic as the most powerful chemical disinfectants. This, coupled with its relative harmlessness to animate life (i.e. mammals), gives oligodynamic silver great potential as a disinfectant.

The best and most environmentally-friendly silver based disinfectants are capable of rendering stored water potable for long period of time as in space stations.

The silver leach rate from the Doulton ceramic is very low and always well below the national recommended limits or equivalent to having a meal using silver cutlery.

Do Doulton ceramic filter removes viruses?

Due to their tiny size viruses theoretically cannot be removed with a 0.2 micron or higher rated absolute filter (or any mechanical filter for that matter). If virus is a concern simply add a commercially available disinfectant such as silver (e.g. Katadyn’s Micropur®) or iodine tablets. Doulton Supersterasyl candle will remove the unpleasant taste and odours of the iodine.

Physically viruses have electrical surface charge that attaches them to other larger particles (free ride). The tight pore-structure of any absolute sub-micron water filter (e.g. Doulton, Katadyn etc.) can remove “free ride” viruses however due to many variables no device should be relied upon viral control.

Activated carbon as another natural adsorber
Doulton uses high quality carbon blends obtained from different raw materials such as lignite, bituminous coal and coconut shells. Active carbon is used for water treatment due to its adsorbing effect with respect to organic and health endangering chemicals.

Activated carbon surfaces are both hydrophobic and oleophilic; that is, they “hate” water but “love” oil. When flow conditions are suitable, dissolved chemicals in water flowing through the carbon media “stick” to the carbon surface in a thin film while the water passes on. This process is call adsorption.

Substances affecting taste and odours such as chlorine, pesticides (lindane, DDT) and trihalogenmethanes (THM’s) are removed by activated carbon. These substances are adsorbed on the large surface area of the active carbon. For visual purpose, one teaspoon of activated carbon have a surface area the size of a football field.

Active carbon is available in granulate (GAC filters), powder (PAC filters) or extruded solid carbon block form (CB filters).

Doulton Ceramic Candles and Cartridge Grades

Sterasyl membrane: (candle and cartridge form): Used for microbiological removal. The only ceramic element in the world to meet the stringent NSF antimony and arsenic extraction test featuring:

  • >99.99% E.coli removal
  • Tested with live Cryptosporidium cyst to 100% removal far exceeding EPA three log cyst reduction requirements
  • 100% efficiency at 0.9 µm absolute (0.5 µm absolute ANSI standard)
  • > 98% efficiency at 0.2 µm
  • > 90% efficiency at 0.05 µm
  • < 0.07 NTU turbidity reduction

Typical application: UV, RO and ozone pre-filter, point-of-use (POU) final polish filter, zero cyst tolerance in bottling water plants using our industrial multi cartridge filters and various other application requiring absolute filtration. Least expensive absolute filter on the market as it is cleanable and reusable for up 60 times. Backwash capable, self-sterilized, no bacteria grow through as encountered in most all synthetic membranes.

Available in candle and open both ends (DOE) cartridge style.

Supersterasyl candle: Used in British Berkefeld gravity filters is a Sterasyl shell packed with granular activated carbon. Available in 2″x7″, 2.75″x7″ and 2″x10″ candle style with long threaded end cap. Custom size and end caps configuration available with minimum kiln firing requirements of 2400 units for all grades of elements

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