Image: Flickr, Oseillo Pictures
Of course, the first question to ask yourself is: does my home really need a water filter? A water filter is only fruitful when it takes bad stuff out of the water without putting any bad stuff back in again. But think for a minute: is it possible that putting a bed for bacterial growth, or chemical treatments, into your water lines could be worse than just drinking the certified safe water which arrives in most homes in developed areas at the twist of a valve? In short, don't rush out to buy a water filter just because it is trendy.
That said, let's take a look at the best water filter when you do need cleaner, softer or tastier water.
No Filter NeededIf you worry about your water quality, check for the consumer confidence report for water in your area at the EPA safe drinking water website. Or contact your local water authorities to get the name of a certified laboratory to test the water at your tap. If you rely on well water, collected rainwater or surface water, you should definitely test your water to protect your health. But the best water filter may be no filter at all!
Carbon CleanIf your concern is related to taste and odor alone, a carbon filter may be the best solution. Carbon filtration relies on the fact that carbon adsorbs contaminants onto its surface. The surface area is maximized on activated carbon during the manufacturing process. The Sears Kenmore 38454 undersink water filter gets our thumbs up because it won best buy recognition from the respected folks at Consumer Reports.
Soft SavingsIf your water is extremely hard, a case can be made that softening the water is the best choice for the environment. The impacts of the energy and materials that go into water softening can be offset by longer appliance life, more washes before clothing goes gray and less detergents needed for effective cleaning. A cation exchange softener, usually installed at the point of entry to the house, takes the "hard" ions calcium and magnesium out of the water, replacing them with sodium and potassium. Our vote for the best ion exchange filters goes to Kinetico for systems which use the energy in the water flowing through them so no electricity is required as well as metered regeneration, which minimizes waste, and dual-tank construction, so the system is never off-line.
Death to DiseasesIf test show the presence of harmful levels of bacteria or parasites in your water, such as Cryptosporidium or Giardia, then you need to take action. Chlorine and other chemical treatments can be effective, but have side effects. Filtration is difficult due to the very small size of some pathogens. But Ultraviolet treatment has proven effective for killing unwanted bugs surfing your water lines. The Trojan UV Max and the UV Pure Hallett systems are the only two technologies certified by NSF for Class A Disinfection Performance, which is necessary in the case of disease-causing bugs. Don't believe advertisements that UV will clean heavy metals or other contaminants out of your water though!
Metals and MixesIf your water test report came back looking like an alphabet soup of -chlor- and -enes, or includes heavy metals, the best system is the one your local water filter professional advises. Reverse osmosis filters can be effective, but will significantly reduce flow rates. Distillation is effective for metals but may carry organic chemicals over in the "clean" water. You may need a combination of filtration technologies. NSF, the certification organization for water filtration devices, has a useful search engine to find water filters making certified claims to address particular pollutants.
More on Water Filters:
Buying a Water Filtration System: Determining Which System Is Best for You
TH Forum: Make of Whole House Water Filter
Clean Water Appears Out of Thin Air with EcoloBlue
Use Sand Filters to Make Rain Water Drinkable