Culligan US-EZ-4 Under-Sink Filter

January 2009. Most under-sink water filters require professional installation by a plumber, but quite a few owners say the Culligan US-EZ-4 water filter can be installed without professional help. The filter is rated for about the same contaminants as the 3-stage PUR faucet-mount, and professional tests find that it can even filter out PFCs, the chemicals used to make Teflon and Goretex. Filters last longer than on a faucet-mount filter -- about 500 gallons or six months on average. One tradeoff for the easy installation and filter changes is that you're locked into using Culligan replacement filters, which may cost more than third-party filters. Another drawback is that plastic parts may not be very durable. If you don't mind more frequent filter changes and want to spend less initially, consider the PUR FM-9400 faucet-mount filter (*est. $35) -- though quite a few owners report that it leaks.

We found a professional test of the Culligan US-EZ-4 water filter at Water Technology Online, where it's run through thorough tests of its ability to filter out PFCs -- a challenging problem in a few geographic areas. Consumer Reports tests a more expensive Culligan under-sink water filter, and a handful of owners review the US-EZ-4 model at Amazon.com.