Coldstream® water filters have full accreditation from US, EU and UK water agencies such as NSF*, are verified by over 5 independent laboratories, and offer hard performance statistics for their filters backed by this portfolio which is continuously updated annually.

*NSF is the National Sanitation Foundation based in the USA, and it is an international organisation which carries out stringent water tests and issues standards.  Coldstream® products are guaranteed to continue to perform at the stringent levels throughout its rated life from 3,000 to 10,000 litres depending on the ceramic water filter model.

Coldstream® water filters do not leach silver.  Coldstream® water filters have passed the material extraction testing with NSF, determining that there is no harmful silver leaching into the effluent water.


Pathogenic Harmful Bacteria
Kiebsiella terrigena
is removed to an absolute degree (defined >99.99%)
based on testing by IAPMO R&T Lab (formerly Envirotek)

Water-Borne Cysts
Cryptosporidium is removed absolutely (defined >99.99%)
based on tests by IAPMO R&T Lab (formerly Envirotek)

Rotavirus spp. is removed (defined 99.97%)
based on tests by IAPMO R&T Lab (formerly Envirotek)

Sediment and Particles
between 0.5 to <1 micron are removed (defined >99.9%)
based on tests by IAPMO R&T Lab (formerly Envirotek)

Organic Chemicals
such as pesticides, herbicides, organic solvents and trihalomethanes
are significantly reduced (>27 to 99%), varying by specific filter

such as free chlorine is significantly reduced (95.2%), varying by specific filter.

Dissolved Heavy Metals
such as lead is significantly reduced (97.8%), varying by specific filter.

Ceramic Structure:
The Coldstream® ceramic is made with a superior grade of diatomaceous earth, and each filter is made up of thousands of overlapping pores, each with an average pore size of 1 micron, and overlapping pore sizes ranging from 0.1 micron to 4-5 microns.  Coldstream® depth filtration has been found effective against reducing the Rotavirus spp. by 99.99% at 5000L and 99.97% at 10000L

The ceramic shell of the Coldstream® filter is an NSF-listed component and is manufactured to meet NSF Standards 42, 53 and P231.  Coldstream® water filters are a few of the only ceramic filters certified under both these NSF standards.

Sentry/Max® Silver-Impregnated
Every Coldstream® ceramic filter has silver permanently locked into the ceramic pore structure, destroying bacteria and preventing colonisation throughout the ceramic element due to the oligodynamic effect.  This is what makes the Coldstream® ceramic filters among the best and most reliable in the world.      

Carbon Core
Comes as a carbon rod (CTO+ and Max) or granular activated carbon (FTO+).  Quality activated carbon can have a surface area of up to 1000m2/g.  This means that just 5 grams of activated carbon can have the same surface area as a football pitch.

Carbon adsorption then ensures that molecules of various chemical impurities collect on the carbon surface.  Coldstream®’s carbon element is responsible for removing bad taste and odours, as well as pesticides, herbicides, organic solvents, and trihalomethanes.

Heavy Metals Reduction Media
Coldstream® utilizes a patented medium to selectively reduce specific and potentially toxic heavy metals such as lead, copper, and mercury, while leaving healthy minerals such as calcium to flow through.

Not at all, for two main reasons:

No Electricity Required
While many distillation systems require significant electrical power consumption, Coldstream® water filters do not need any electricity at all, using mechanical pressure to filter water.  Converse to many popular water systems now which include a fairly inefficient heating system for instant hot and cold water dispensing, Coldstream® filters are purely for the purpose of providing quality drinking water, and will not blow up your energy bill.

Long Lifespan
The superb product reliability of Coldstream® water filters allows it to live way beyond rated levels of performance

For example, the Max® filter we carry has a total guaranteed performance of 10,000 litres for rated metal reduction performance.  However, customers in Singapore will be able to easily use it beyond this capacity, and with proper cleaning, there will be no cracks in the ceramic.

Coldstream® is a rare gem that trades frivolity for solid filtration integrity and reliability.

In a multi-layered ceramic filter, anti-bacterial elements are even more critical because carbon is a natural growth medium for bacteria.  In carbon-only filter elements, which are commonly found in many multi-stage systems, the carbon filter often ends up as being a bacteria repository if not changed regularly.

The pure silver in Coldstream® ceramic elements is a specially assimilated self-sterilizing bacteriostatic agent, which destroys bacteria through the oligodynamic effect.  The result is that bacterial growth is inhibited within the Coldstream® FTO+/Sentry/CTO+/Max® ceramic. Bacterial “grow-through” is a huge problem, especially on the ground in disaster-relief situations, and it is especially common with typical ceramic filter elements.

The silver content in Coldstream® ceramic elements stands at about 0.02 – 0.03% of the dry weight, which is well within the allowable levels recommended by the World Health Organization and the EPA.  Because of the silver, Coldstream® filter elements do not require any sterilization, even after cleaning/scrubbing.

Coldstream® is a reliable and trusted water filtration brand.

Coldstream® is a relatively new company.  It is using new technology to achieve better product quality.  The company has a robust Research & Development team.  

Coldstream® filters are produced with solar energy.  Coldstream®’s production process is aimed at going carbon neutral.  The company is energy self-sufficient based on its solar power generation which gives a manufacturing cost advantage.  There is also a plan underway for environmentally friendly disposal of used ceramic filters so that these can be recycled and used as high grade soil amendments.  In these days of circular economies, such considerations are important for tomorrow’s world.


Coldstream® Stainless Steel Housings are solid, safe, and fully made in the UK.  No sharp edges.  These Housings can last for decades.  Coldstream® stainless steel filter housings have a brass element which helps to provide further water disinfection.

Coldstream® Ceramic Water Filters are the best-in-class among ceramic water filters available internationally.  It has virus-reduction properties.  The all-in-one Coldstream® Max Ceramic Filter removes harmful bacteria, waterborne cysts, viruses, and reduces chemicals, heavy metals as well as fluoride.

See the Coldstream® Ceramic Water Filter Performance Data Sheet.

The superior performance of Coldstream® Ceramic Water Filters leads to economic daily use.   Customers now need to have just one Coldstream® Max Ceramic water filter for fluoride reduction, instead of needing two separate filter stages.  

The Coldstream® Max Ceramic Water Filter has a unique blue ceramic layer.  This provides an indicator of when to replace the Ceramic Filter.  Once the blue layer has been washed off, it is time to replace the Ceramic Filter.

For customers who have the Doulton® Dual/Double Countertop or Undersink Housings, there is no longer any need to have a separate Fluoride reduction filter, with the Coldstream® Max Water Filter system which also reduces fluoride. 

To save countertop or under-counter space, Arkwater provides a trade-in discount for its customers who purchase a new Coldstream® Single Housing to replace their old Doulton® Dual/Double Housing.  Contact information@arkwater.com for trade-in enquiries.

The Coldstream® ceramic water filters emit fine non-toxic particles upon first use due to the manufacturing process.

Remember to read the Coldstream® Manufacturer’s Instructions, and flush each ceramic filter through with at least 20 litres of source water before use, or roughly 10 minutes.

This can vary depending on usage and water quality, but the best indication to do so is when your water flow becomes noticeably less than normal.  This reduction in flow is due to contaminants blocking the water pathway, proving that the ceramic element is working.

Gently clean the ceramic water filter with a scouring pad holding the plastic mount up, until the clean ceramic returns.  Try not to rub too heavily or use overly abrasive material.  Ensure that the end of the plastic mount does not come into contact with unfiltered water.

Do not use soap as it can potentially damage and clog the ceramic structure.

Yes, regular blocking would be simply due to high turbidity in the water supply.  This proves that the filter is working effectively.  It is the ceramic filtering out contaminants which reduces the water flow.

If the water flow is affected too often or too much, it may be beneficial to use a pre-filter upstream of the ceramic filter.  This prevents the ceramic from becoming blocked too quickly, minimizing cleaning and extending the life of the filter.

Unscrew the body from the head and wipe the outer surface and inside of the body with a soft cloth dampened with warm water.  Do not attempt to clean the filter spout as this could cause contamination of the filtered water if wrongly cleaned.

If there’s time before you leave on a holiday, take out the Ceramic water filter, scrub it clean and lay it flat to dry on a clean towel.  But if you haven’t done this, don’t worry.

Due to its self-sterilising nature, Coldstream® ceramic filters will not be affected by a lack of use for a period of time.  If normal use of the filter is interrupted by holidays or vacations, the growth of harmless heterotrophic bacteria may result in a ‘flat’ or ‘stale’ taste for a period of time when use resumes.

Flushing the filter system for several minutes after any prolonged period of inactivity will eliminate the problem.

When the bad taste and odour of unfiltered water returns, it indicates the activated carbon in the ceramic filter has been exhausted and change is recommended.

Please note the Coldstream® ceramic shell can continue to remove pathogenic harmful bacteria even after the carbon is exhausted.

Yes, and keep in mind that the Operating Temperature Range of the Coldstream Ceramic Filter elements is 5 to 70