The 3 Best Under-Sink Filters From Our Tests Keep Clean Water on Tap
Tired of plastic water bottles piling up? A top-rated water filter can spare your wallet and recycling bin, as well as the environment
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Under-sink water filters can deliver cleaner, better-tasting drinking water the old-fashioned way: from a spout.
They’re more effective at removing lead, chlorine, and other contaminants than popular refrigerator filters and water filter pitchers. Plus, “under-sink water filters are inherently more convenient than pitchers, with higher filter capacity,” says Joan Muratore, who oversees the water filter lab at Consumer Reports. “There’s no need to pour water into a pitcher and wait. You just flip the lever and the filtered water flows.”
Which Under-Sink Water Filter Removes Most Contaminants?
Under-sink reverse osmosis water filters are recommended if your water contains a wide range of contaminants or bacteria. (To find out, check the water-quality report issued annually by your water supplier, or if you have a well, have it tested.) Reverse osmosis filters remove water contaminants like lead, volatile organic compounds (VOCs), PFAS, arsenic, bacteria, and viruses, according to the Environmental Protection Agency. Reverse-osmosis filters force water through a semi-permeable membrane, separating it into filtered, drinkable water and contaminated "reject water." So although these systems improve water quality, they also generate a lot of waste water—as much as 5 gallons for every gallon of filtered water, the EPA says.
For lead, chlorine, and other contaminants, standard under-sink filters that meet NSF/ANSI certification should do the trick. (NSF International and the American National Standards Institute develop water filtration standards.) All under-sink water filters in CR’s ratings are certified to the NSF standard for removing lead and chlorine.
How CR Tests Under-Sink Water Filters
To test flavor and odor reduction, CR spikes a “control water” sample with common taints that smell or taste like metal, compost, damp soil, a sewage treatment plant, or a swimming pool. Then trained water testers filter it and examine how well the filter removes those taints compared with pure spring water. We measure flow rate by the time it takes to filter 1 gallon of water. Our clogging score reflects how much the filter’s flow rate slows over the course of the cartridge’s lifespan.
How Do You Choose an Under-Sink Water Filter?
Consider cost, type, and flow rate, as well as filter life, features, and which contaminants you need to remove. Most importantly, choose a water filter that’s certified by NSF, Water Quality Association (WQA), or the International Association of Plumbing & Mechanical Officials (IAPMO).
Five under-sink water filters in our ratings come with a filter-life indicator that alerts you when it’s time to buy a new cartridge. Four of these six filters are certified to remove PFAS (per- and polyfluoroalkyl substances) from your water—those toxic "forever chemicals" implicated in health concerns like cancer, thyroid disease, liver damage, fertility problems, and immune system disorders, as well as increased cholesterol levels, obesity, and hormonal disorders.
For more information on the different types of water filters out there, check out our water filter buying guide. CR members can read on for ratings and reviews of the three best under-sink water filters from CR’s tests. Members can also dive in to our complete water filter ratings for more options.
Best Under-Sink Water Filters
