Why DDK Purest X is your best choice!

Why filter your drinking water?

Only two reasons really, taste and health.

Removing chlorine and other chemicals while leaving in the healthful natural minerals greatly improves the taste of your drinking water, coffee, tea, juices and other beverages. Filtering your tap water will help everything you make or cook that has water in it taste better.

Health concerns, especially for young children who are developing and growing rapidly and for people whose health is compromised through illness or age. Disease-causing microorganisms like Cryptosporidium and Giardia, are dangerous even for healthy adults. The DDK Purest X filters these and other pathogens out of your drinking water. Our ground water is increasingly contaminated with everything from pesticides and industrial chemicals to the drugs we take. Click here to see an article in Science News about pharmaceutical contamination of lakes, streams, and groundwater.

Sometimes we don’t find out about contaminants until we’ve been drinking them for years, too late for some. At other times, contaminant levels in our water may “spike” and then fall back to EPA “acceptable” levels. Municipal water supplies are only required to report annual average contaminant levels, so if a spike affected your health, you may never know what the cause really was.

Even chlorination, the process of sanitizing our drinking water, leaves trace amounts of byproducts that are recognized as carcinogens. Note that there is some disagreement among professionals about what “acceptable” levels of contaminants are. For instance, the National Cancer Institute has said “No level of exposure to a chemical carcinogen should be considered toxicologically insignificant for humans.”

Filtering your tap water is a proactive effort to protect yourself and your family from current and unknown future threats.

The EPA has published a very complete reference to drinking water issues. Click here to download a PDF version of their brochure “Water on Tap”.

What do I do with the old Seagull (TM) pre-filter (in blue, transparent housing)?

You can safely remove it. The DDK Purest X Replacement Cartridge has its own pre-filter incoporated within itself.


Can The DDK Purest X filter remove arsenic?


There are two main types of arsenic found in water, trivalent and pentavalent. Chlorination actually changes the chemical structure of the arsenic to the pentavalent form. The DDK Purest X filter will remove the pentavalent arsenic found in chlorinated water.

Can The DDK Purest X filter remove bacteria and viruses?


Most harmful bacteria are greater than 0.4 micron in size. In almost all cases, a correctly engineered, submicron filtration system such as The DDK Purest X will remove disease bacteria like E.Coil, fecal coliform, and Salmonella, through the combination of submicron sieving and electrokinetic attraction.

Viruses typically cannot function (metabolize or reproduce) outside of a host organism, so it is possible that waterborne viruses, which infect bacteria and other microorganisms, may be removed by the filter when the host organism is removed. Viruses are, however, much smaller than bacteria, and it is also possible that they could slip through the filter on their own. Thus we only recommend using The DDK Purest X with microbiologically safe, potable water supplies.

Bacteria and viruses are not the major problem in municipal water systems. Mercury, lead and carcinogenic chemical residues are the main concerns. The DDK Purest X filter will remove lead, mercury, and many toxic or carcinogenic chemical residues including the hazardous byproducts of chlorination (chloroforms, THMs) increasingly found in water classified as potable.

What Is the size of the The DDK Purest X filtration?

The DDK Purest X filter is carefully engineered for nominal pore sizes of 0.4 microns (a micron is a micro-meter or one millionth of a meter).

How long will The DDK Purest X filter cartridge last?

1 year or 750 gallons, whichever comes first.

The life of the filter is directly related to two factors, the purity of the input water and the desired performance with regard to the various contaminants. To see a summary of testing done in 2000 and 2001 by Spectrum Labs, a nationally recognized independent laboratory, click here. For a PDF file of the full report, click here.

Note that contaminant levels in the test water were artificially high (10 to over 1000 times higher than those routinely found in municipal water systems). Even after filtering 750 gallons, The DDK Purest X still produced exceptional results. Filter life is determined by the amount of contaminants removed. Modern municipal water systems have greatly reduced contaminant levels. Actual gallons of water filtered before replacement is recommended will therefore be substantially higher than the test quantities. Even so, annual replacement of the filter is recommended to assure maximum contaminant reduction. Operating pressure range = 30 to 125 psi.

Can The DDK Purest X be used on well water?

Small amounts of hydrogen sulfide and iron typically found in well water will be removed but large amounts will eventually cause reduced flow requiring cartridge replacement. Results will depend on your well water makeup. In any case, annual replacement is recommended.

This system is not to be used on microbiologically unsafe water.

What other kinds of water filtration/purification systems are available in the market and why are they bad?

Distillation – Distilled water has a flat taste, and may contain bacteria if the temperature is not hot enough long enough. Volatile organic compounds (VOCs), which may boil at temperatures near the boiling point of water, may not be removed by distillation. Only a fraction of the water used by these systems is captured as drinking water. Oxygen and healthful dissolved minerals are removed through distillation resulting in the flat taste associated with distilled water. If distilled water is stored in a holding tank, pathogens may grow in the water. Doctors generally do not recommend drinking distilled water because it upsets the ph level in the stomach and can cause acid reflux.

Reverse Osmosis – RO systems remove everything including oxygen and healthful dissolved minerals. This accounts for the flat taste associated with RO filtered water. If RO water is stored in a holding tank, pathogens may grow in the water. Only a fraction of the water used by these systems is captured as drinking water. Many systems flush as much as 8 gallons of water down the drain to produce 1 gallon of RO water. As with distilled water, Doctors generally do not recommend drinking RO water because it upsets the ph level in the stomach and can cause acid reflux.

Ultraviolet (UV) Radiation – UV systems eliminate bacteria, viruses and fungi, but require additional filtration to remove turbidity and chemical contaminants.

Sediment Filters – These are useful as pre-filters for water with a high sediment content. They physically strain out dirt but are ineffective against most contaminants.

Granulated Activated Carbon/Charcoal (GAC) – These systems function well as dechlorinators, but have no ability to remove pathogens from water. Over time the filter may develop channels or passages that reduce its effectiveness.

Carbon Block – Made by compressing carbon mixed with an adhesive to prevent channeling, carbon block filters are greatly superior to loose particle GAO, although they often yield a low water flow-rate and require a carefully manufactured structure for consistent results.

Hollow Fibers – Very tight pore size to reduce bacteria is possible with hollow plastic fibers, but they are fragile and any discontinuities allow the passage of pathogens through the filter. Hollow fiber filters do not remove organic contaminants.

Ceramic Candle Filters – Ceramics are good as sediment filters and may remove some bacteria. Typically, they require high input water pressures, clog quickly and need to be cleaned frequently.

Bottled Water – Bottled water is expensive and inconvenient, and while standards for water bottlers have become more stringent in recent years, they are still not as stringent as standards for municipal water systems. Also, quality tests are not required as frequently as tests on municipal water systems.

How Can I Compare Filter Systems?

This is tough because there is no governing body that requires a standard set of tests. California, Iowa, Massachusetts and Wisconsin all have regulations that require testing, but ONLY for claims the manufacturer makes in advertising materials distributed in their respective states. In other words you must directly compare each manufacturer’s claims to see if they both claim to remove the same contaminants.

The NSF has comprehensive standards, but they are not mandatory. Two important ones for drinking water filtration systems are NSF/ANSI Standard 42, which only covers filter systems designed to reduce specific aesthetic or non-health-related contaminants (chlorine, taste and odor, and particulates) and 53, which covers systems designed to reduce specific health-related contaminants, such as Cryptosporidium, Giardia, lead, volatile organic chemicals (VOCs), MTBE (methyl tertiary-butyl ether).

Then there is the question of who did the tests and how. Was it a nationally recognized laboratory? Did they use the more rigid EPA protocols for testing? Reputable manufacturers who are honestly representing the performance of their filters will gladly give you all this information. Of course The DDK Purest X has been tested to comply with both of these using the more rigorous EPA protocols.

How to install on a “female tap head”?

Install instructions