Under-sink model water filters offer the advantage of being plumbed-in down under the sink cabinet so that they are out of sight, out of the way, and don't clutter up the sink counter-top. They are, by far, the most popular models for homeowners and those who are likely to stay put for at least the next several years.Another advantage of the under-sink models is that, since they are under the cabinet and out of the way, they can be larger than what is usually practical for counter-top filters. And since all good water filters are bacteriostatic, larger means a longer service life before you will need to consider replacing them. For the most popular "sealed" filter units (as opposed to replaceable cartridge type units), service life is typically in the range of 5-6 years for households up to four people.
The under-sink water filters we at ESD market come complete with a "saddle valve" for easy cold water line tap-in, neoprene hosing for connector lines, and an attractive Touch-Flow gooseneck faucet for dispensing drinking water separate from the kitchen sink faucet's straight tap water. Installation is relatively simple and is accomplished by most homeowners by themselves or by contracting with a local handyman or plumber. Once installed, they are usually good for several years and replacement is simply a matter of disconnecting the old and connecting the new -- no new plumbing required.H2O International makes a range of sizes and types of under-sink water filters. See our display of them by clicking HERE.
FAQs about GAC/KDF water filters:
-- Why water filters? Doesn't distillation produce a more "pure" water?
-- Why not Reverse Osmosis (RO)? Isn't RO better than water filters?
-- What about lead (Pb) removal/reduction?
-- What health hazard contaminants are removed/reduced by GAC/KDF filtration?
-- Why the combination of GAC and KDF?
-- How long do water filters last?
Q -- Why water filters? Doesn't distillation produce a more "pure" water?
A -- Yep. Trouble is, distilling water also removes some of the natural components of water that are aesthetically pleasing to the taste -- one of them being air. The most common complaint about distilled water is that it tastes "flat." The combination of GAC (Granular Activated Carbon) and KDF (a synthetic filter media) employed by H2O International in the manufacture of their water filter product line captures perhaps the ideal degree of water purification. By removing and/or reducing things of a chemical nature, and by NOT removing the more aesthetically pleasing components, water filtration is by far the more popular, most cost-effective and most available drinking water production technology on the market.
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Q -- Why not Reverse Osmosis (RO)? Isn't RO better than water filters?
A -- Yes, RO is more efficient than GAC/KDF water filtration at removing certain types of contaminants. Your question should be: "Do those contaminants exist in my incoming water?"
For homes served by regulated (municipal or commercial) water treatment facilities, the incoming water is surely subject to EPA regulation. Water treatment facilities are obliged to record daily the levels (or presence/absence) of certain contaminants they are putting out into the water main delivery system. If they exceed those levels (limits), they must make that report to the EPA, and for certain contaminants of a health hazard nature, must publish a notice in a local newspaper. You've probably seen or heard of notices being published about high THM levels, or high nitrate levels. In short, the liklihood of your treated tap water having anything in it that a water filter would not remove/reduce, that would require RO to remove it, is very slim, indeed.
For probably 90%+ of all tap water circumstances, RO would represent expensive overkill technology. For the really dangerous stuff, like the chlorine itself or some of the common chlorine byproducts such as the Trihalomethane group (THMs), GAC/KDF represents the ideal water treatment technology. THMs, which include some known carcinogen nasties like chloroform, are easily removed by GAC/KDF filtration. RO will remove them, too, but at a vastly more expensive overhead to do the same job.
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Q -- What about lead (Pb) removal/reduction?
A -- Do you suspect you have lead in your water? Well, don't just suspect it, KNOW whether you have lead in your water by testing for it. You may need to incur the expense of water testing by hiring the job done by a private laboratory. If you DO have lead in your water, you need to discover where it is coming from. Is it in the water when it arrives at your house, or is the water picking-up the lead once it meets your household plumbing? In nearly all cases, the introduction of lead into household water is attributable to the plumbing in the house itself -- NOT the raw tap water as it is delivered to the house.
Your first step is to get rid of the plumbing that is introducing the lead. Typically, that will be older copper piping that was soldered (sweat jointed) together with lead-based solder. Today, all solder is lead-free, but older piping may have used leaded solder for the pipe joints and fittings. If you are unable to replace all that plumbing with no-lead soldered joints and fittings (you don't own the property or other reason), then your second option would be to install a RO unit.
Lead is one of the contaminants (of a mineral/metal nature) that GAC/KDF is not effective at reducing. That would be a job for Reverse Osmosis. But the key is to KNOW. You can spend a lot of money with the initial purchase and with ongoing (monthly) expenses as well by treating for "phantom" contaminations. Know whether you have a certain contaminant in your water before incurring the expense of treating for it.
By far, the broadest range of catch-all contaminant removal/reduction is represented by GAC/KDF filtration media. There are some other contaminants that might (rarely) be present in the water that GAC/KDF will not effectively remove/reduce, indicating the justification for RO.
I'm not a detractor of RO water treatment technology -- I've just seen RO over-sold to a lot of customers who really didn't need it, and really could scarcely afford it, and where a GAC/KDF water filtration system would have done the job just as well at a fraction of the cost. If RO is indicated, that's the way to go. If not, the chances are strong that GAC/KDF will represent the most efficient and cost-effective technology.
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Q -- What health hazard contaminants are removed/reduced by GAC/KDF filtration?
A -- Quite oddly, perhaps the most serious health hazard chemical that is likely to be present in your incoming tap water is required by law to be in there -- chlorine.
Chlorine is a great disinfectant. Household bleach is a mild chlorine solution, and by that definition, municipal tap water is simply an even milder bleach. The eradication of nearly all occurrences of cholera and other water-borne diseases in the USA are largely attributable to the introduction of chlorine disinfection to water distribution systems. All states in the USA now mandate, regulate and enforce the disinfection of tap waters, and most treatment facilities will employ chlorine to do that disinfecting.
But, as with the insecticide DDT, it can later be discovered that there are (at least) two edges to that sword.
For cities and communities that draw their raw water from "surface water," the potential for the chlorine disinfectant bonding with naturally occuring organic acids to form dangerous chlorinated compounds is at its highest. "Surface water" is defined as any natural and open body of water: rivers, lakes, ponds, reservoirs, etc. In such waters, life abounds. And where there is life, there is death. The bottoms of natural bodies of water is a veritable "soup" of relatively harmless (in and of themselves) humic and fumic acids, formed by the decomposition of plant and animal materials.
The problem occurs when water with those organic acids is drawn-up by the treatment facility, and zapped with chlorine as a near final stage of treatment, before being released to the distribution system. If you zap such water with chlorine, it will always form chlorinated compounds such as chloroform. Chloroform and other compounds in the Trihalomethane group (THMs) are known carcinogens. It should be considered dangerous to drink straight tap water that is produced from a surface water source.
The list of chlorinated compounds that represent known health hazards is long and mostly well-recognized. Check a list of carcinogenic (cancer-causing) chemical compounds and look for the tell-tale "chlor" as part of the chemical name. The "chlor" part says it's based on (or around) chlorine.
GAC/KDF is a very appropriate and cost-effective technology for the removal/reduction of chlorinated compounds and most other contaminants of a chemical nature.
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Q -- Why the combination of GAC and KDF?
A -- Both Granular Activated Carbon (GAC) and the synthetic media known as KDF are excellent water filtration media by themselves. Each have their own strengths and weaknesses, so by combining the two you get a water filter that represents the best of both worlds of granular filter media.
One of the side benefits of combining GAC with KDF is that KDF is "bacteriostatic," meaning it represents an inhospitable environment for bacterial growth. By employing KDF along with the GAC in a water filter, the entire water filter is rendered bacteriostatic. Bacteriostatic water filters can be made larger than non-bacteriostatic filters.
A filter that is not bacteriostatic should be changed-out at least every six months to avoid the possibility of bacterial contamination. If not bacteriostatic, the inside of a water filter would be a nearly ideal place to cultivate a cuture of bacteria. It's wet, warm, dark -- perfect.
By making a filter bacteriostatic, so that it cannot come to represent a bacterial "tea bag" and make you sick, filters can be made large enough to serve five or more years without having to mess with them at all. The only limiter on the service life of a bacteriostatic water filter is the size of the media bed -- how much it will be capable of absorbing and adsorbing.
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Q -- How long do water filters last?
A -- The only sensible way to rate a water filter, anybody's water filter, is by the number of gallons of flow-through it should be expected to treat before needing replaced. There are simply too many variables to take into account to give a straight answer in terms of number of months or years.
Providing the filter is bacteriostatic, the only limiter on its service life will be the capacity of the media bed of that filter to continue to remove/reduce contaminants to an adequate degree. Variables such as the average chlorine dosage your water treatment facility puts into the tap water will affect the service life of water filters. And of course, those average dosage levels can vary quite a bit even between neighboring communities.
Most water filters will be rated as to the number of gallons of flow-through it should be expected to treat. Of course, that presumes a universal average for chlorine dosage and other variable factors. It must be left to the end user to determine their own usage, in gallons per month or gallons per year, and then extrapolate to arrive at an expected service life span.
Some general and average factors you can use to help do some calculating:
The average consumption of water for the United States is right at 80 gallons per person per day. Note: that is water usage for all purposes (washing, flushing, rinsing, drinking, cooking, drink preparations, etc.), not just ingesting. If you are considering a whole house unit, use that 80 gallons per person per day figure to estimate how long a certain filter should be expected to last you. Multiply 80 times the number of people served, multiply that times 365 (days per year) and divide that figure into the total gallons capacity rating of the water filter to know the number of years the filter should last.
For strictly drinking, cooking, drink preparation, and other consumable purposes (POU units), use the figure 5 gallons per person per day for your calculations.
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To check out the undersink water filters offered by ESD, click HERE.To discuss your water treatment needs with ESD please feel free to e-mail me at or call 1-304-721-8380 weekdays 9am - 5pm Eastern.
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