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Installing an under-sink water filter is a quick, easy and cost-effective way to provide safe, delicious water to your faucet.Upgrading may be more important than you realize: While America has the safest drinking water in the world, it’s far from perfect.Lead-contaminated tap water is an ongoing problem, not just in places like Flint, Michigan.
As many as 10 million American homes are connected to water sources through lead pipes and service lines, which is why the Environmental Protection Agency (EPA) is strengthening its lead and copper regulations.Then there’s the question of PFAS (short for perfluorinated and polyfluoroalkyl substances).A hot topic at GH’s 2021 Raising the Green Bar Sustainability Summit, these so-called permanent chemicals — used to make some consumer products as well as firefighting foam — are polluting groundwater supplies at such an alarming rate that the EPA issued a report on Health Advisory.
But even if your home’s tap water isn’t polluted, it can still have a weird smell because public water systems use chlorine to kill disease-causing bacteria like Salmonella and Campylobacter.That’s why the experts at the Good Housekeeping Institute test all types of water filtration products, from simple water filters to elaborate whole-house solutions.While these options have their place in the market, our pros say that under-sink water filters are best for most homes.
As the name suggests, under-sink filters are installed in cabinets below the kitchen sink; the dispenser is usually located next to your main kitchen faucet.Our engineers have found that the best under-sink filters do an excellent job of removing contaminants without clogging.They do so prudently.“Under sink filters take up some cabinet space, but they don’t clutter the sink deck like countertop filters, and they’re not as bulky as faucet-mounted filters,” says lead engineer Rachel Rothman.Good Housekeeping Academy, she oversees our water filter review.
To narrow the list of contenders, our experts considered only water filters certified by NSF International, the organization that sets public health standards and certification programs for the industry.Over the years, we have reviewed many data points, such as checking that filters are certified to NSF standards (some standards only cover lead, like NSF 372, while others also include agricultural and industrial toxins, like NSF 401).As part of our hands-on testing, our engineers considered factors such as flow rate and how easy it would be to install and replace the filter.”We also took into account the brand’s track record and reliability, testing water filters for decades in our homes and labs,” Rothman said.
Over the past 25 years, Aquasana has built its reputation as a leader in water filtration.Its 3-stage under-sink filter has earned the highest rating from our engineers thanks to its innovative multi-filtration technology, which is NSF certified to capture 77 contaminants including heavy metals, pesticides, pharmaceuticals and water treatment Disinfectant.It’s also one of the few filters certified to remove PFAS, which is a big reason why Dr. Birnur Aral, Director of GH’s Health, Beauty, Environment and Sustainability Laboratory, keeps this Aquasana in his home.As she has proven, even though she uses it every morning for everything from cooking to refilling the coffee machine, the unit can do all the filtration without premature clogging or a drop in flow – plenty throughout the day, of course Hydrate!• Filter Types: Pre-Filter, Activated Carbon, and Catalytic Carbon with Ion Exchange • Filter Capacity: 800 gallons • Annual Filter Cost: $140
While we haven’t tested this system, Culligan is a trusted name in water filtration with a proven track record in past Good Housekeeping reviews.In addition to the low initial cost, replacement filters are relatively inexpensive.It’s certified to capture a variety of pollutants, including lead, mercury, and cysts, and claims to reduce chlorine taste and odor.That said, its granular activated carbon filtration isn’t as powerful as other top picks: For example, the filter isn’t certified to NSF Standard 401, which covers pharmaceuticals, herbicides, and pesticides.The EZ-Change can filter 500 gallons before needing replacement.That’s respectable for an inexpensive filter, but less than the 700 to 800 gallons we’ve seen in other models.• Filter Type: Granular Activated Carbon • Filter Capacity: 400 gallons • Annual Filter Cost: $80
If cabinet storage in your kitchen is at a premium, you’ll love the compact design of the MultiPure under-sink filter.In field testing, our experts noted that the 5.8″ x 5.8″ x 8.5″ enclosure can be mounted on a cabinet wall, leaving plenty of room for other items under the sink. Initial installation is simple, and filter replacement is easy Certified to NSF Standards 42, 53 and 401, the solid carbon block filter excels at capturing a wide range of contaminants. Our testers report that if the filter is changed annually, the flow remains strong and Stable when household water usage peaks.• Filter Type: Solid Carbon Block• Filter Capacity: 750 Gallons• Yearly Filter Cost: $96
While not cheap, Waterdrop under-sink filters cost hundreds of dollars less than other reverse osmosis (RO) systems.According to the manufacturer, its tankless design saves space and is also more water efficient.While we have not yet tested the unit, past reports on RO technology have confirmed its efficacy in capturing contaminants.Waterdrop is certified to NSF 58, one of the highest standards, so it can withstand everything from heavy metals to pharmaceuticals to PFAS.Our engineers love the smart design of the unit, including a filter indicator light on the faucet and a smart monitoring panel that tells you the amount of TDS or total dissolved solids filtered out of the water.One caveat: Unlike the other filters in this roundup, the Waterdrop is not suitable for well water because the presence of large particles can cause clogging.
Most household water filters are point-of-use, which means they are designed to filter water from a single faucet.This article focuses on under-sink filters with faucet-style dispensers; our experts love them because they combine performance with a clean, space-saving design.Other types include:
✔️ Water Bottle Filters: These water jugs are an inexpensive, easy option with an onboard filter that allows water to pass through.They’re good for small volumes, but they’re not the best choice if you use filtered water for cooking and drinking or have several family members.
✔️ Refrigerator water filter: If your refrigerator has a water dispenser, it’s possible that it also has a filter, usually on the top of the unit, although some manufacturers hide them behind a trim panel on the bottom.A word of caution: According to the Home Appliance Manufacturers Association, there are a lot of fake refrigerator filters for sale online, and the poor design means they can do more harm than good.Make sure any replacements you buy are certified to at least NSF Standard 42 to ensure that the physical components of the filter will not leach contaminants into the water, and that it is a manufacturer-approved filter.
✔️ Countertop Water Filter: With this option, the filter sits on the countertop and connects directly to your faucet.This means that you don’t need to modify the plumbing, and it can be installed easily.But these filters clutter the sink deck, and they don’t work with pull-down faucets.
✔️ Faucet Mounted Water Filter: In this setup, the filter is screwed directly onto your faucet.Most let you switch between filtered and unfiltered water.While very easy to set up, they look clunky, and they also don’t work with pull-down faucets.
✔️ Whole House Water Filters: They are installed on a home’s main water main to capture sediment and other large particles commonly found in well water.Our experts recommend installing a second point-of-use filter to remove smaller contaminants.
Most household filters work by passing water through an active material, such as carbon or charcoal, to remove impurities through a chemical process.In contrast, reverse osmosis (RO) captures pollutants by pushing pressurized water through a semipermeable membrane.This process is very efficient.
The downside is that RO systems are usually expensive and waste a lot of water, and they require a large storage tank, so they cannot be installed under a sink.But the technology continues to innovate, including smaller, tankless designs like the Waterdrop version on our list.Even so, before purchasing an RO water filter, our experts recommend that you test your water to determine if a traditional filter will provide adequate protection.
If you draw water from your city, you should receive an annual Consumer Confidence Report (CCR) telling you which contaminants have been detected in your municipal water supply in the past year.This is useful information, but if hazardous materials leave the utility and still get into your water, including lead pipes in your home (if it was built before 1986).There are also 13 million US households that use private wells but do not receive CCR.That’s why it’s a good idea to test your water regularly.
DIY kits, including those from GH Seal Holder Safe Home, are affordable and easy to use; Safe Home’s kits are $30 for a city water supply, and $35 for a private well version.”You need to know what’s in your water,” said Chris Myers, president of the Environmental Lab, which makes the kit.”That way you can focus the laser on the water filter and it will remove what you need to remove.”
While each system is unique, most systems come with filter housings that mount to the inside wall of the sink cabinet.One end of the filter is connected to your cold water line with a flexible connection.The second connection goes from the other end of the filter to the dispenser, which is located on your sink deck.
Installing the dispenser is often the trickiest part, as it involves drilling holes in the countertop.A competent DIYer should be able to handle the project, but if you’re inexperienced, it might be worth hiring a plumber, especially if your plumbing needs to be modified.