Water filtration is big business, netting $3 billion dollars annually for manufacturers. The industry should only get bigger as concerns over water safety proliferate, owing in part to the nation's aging infrastructure of water distribution pipes. In 2010, public-water system health violations affected 108 million Americans, an annual increase of 27 percent, according to the Environmental Protection Agency. That has many manufacturers vying to build a better water filter, as Consumer Reports' latest water filter reviews found.
We tested the five main types of water filters: carafe, faucet-mounted, countertop, undersink, and reverse-osmosis. Our engineers spiked water with lead and chloroform (a surrogate for organic compounds like atrazine and benzene) and ran the contaminated water through each product. The best filters captured contaminants without slowing water flow to a trickle or clogging prematurely.
Carafes are installation-free, but require refilling. Faucet-mounted models are fairly easy to install, and they allow you to toggle between filtered and unfiltered water, but they can't be used with most pull-down or spray faucets. Countertop models filter large volumes of water without plumbing modification, if you don't mind the visual clutter. Undersink and reverse-osmosis filters are both out of sight, though they're the hardest to install.
Among the newer designs is the Cuisinart Clean Water WCH-1500, $150, a cross between a carafe and a countertop system. The two-gallon tank dispenses chilled, room temperature, and heated water. While very good or better at removing impurities, the Cuisinart’s relatively slow flow rate kept it off our recommended list.
We also tested the Pur FM-3700B, a $30 faucet-mounted filter that touts one-click installation. It's actually a bit more involved than that, since you have to replace your faucet's standard aerator with one supplied by the manufacturer. More importantly, the new aerator may not work if you have a pull-down or spray faucet. But if you can get the aerator on, installing the Pur is indeed a one-click operation, plus the filter does a very good job overall of filtering water.
Besides performance and ease of use, you of course need to think about cost when choosing a filter. You can pay as little as $15 for a carafe filter or as much as $1,800 for a reverse-osmosis system. Determining what contaminants may be lurking in your tap water is helpful in making the right decision. Read our complete buying guide on water filters for details on how to do this, as well as access to the full Ratings of water filters.