Our pick
Aquasana AQ-5200
Certified for the most contaminants, widely available, affordable, and compact, the Aquasana AQ-5200 is the under-sink water filter system we’d look for first.
Buying Options
*At the time of publishing, the price was $153.
The Aquasana AQ-5200 is ANSI/NSF-certified to virtually eliminate a wide array of contaminants, including lead, mercury, volatile organic compounds, pharmaceuticals, and other materials that few of its competitors catch. It’s one of a handful of filters certified for PFOA and PFOS, compounds involved in the manufacture of nonstick materials that received an EPA Health Advisory in February 2019. In 2022, it was also certified to remove microplastics, raising its total certifications from 77 to 78.
Replacement filters cost about $60 for a set, or $120 per year on Aquasana’s recommended six-month replacement cycle. And, being barely larger than a couple of cans of soda, the system doesn’t take up a lot of valuable room under your sink. This widely available system uses high-quality metal hardware, and its faucet comes in multiple finishes.
Runner-up
A.O. Smith AO-US-200
Identical to the Aquasana AQ-5200 in certifications, specs, and size, the A.O. Smith AO-US-200 is exclusive to Lowe’s, so not as widely available.
Buying Options
*At the time of publishing, the price was $140.
The A.O. Smith AO-US-200 is identical to the Aquasana AQ-5200 in every important respect. (That’s because A.O. Smith bought Aquasana in 2016.) It has the same exceptional certifications, all-metal hardware, and compact form, but because it’s sold only at Lowe’s it’s not as widely available, and its faucet comes in only one finish: brushed nickel. If that suits your style, we recommend shopping between the two models by price: one or the other is frequently on sale. Filter-replacement costs are similar: about $60 for a set, or $120 a year on A.O. Smith’s recommended six-month cycle.
Upgrade pick
Aquasana AQ-5300+ Max Flow
With the same great certifications but a higher flow rate and filter capacity, the AQ-5300+ works for homes that use a lot of water—but it costs a bit more and takes up more space under the sink.
Buying Options
*At the time of publishing, the price was $196.
The Aquasana AQ-5300+ Max Flow has the same exceptional 77 ANSI/NSF certifications as our other top picks but offers higher flow (0.72 versus 0.5 gallons per minute) and filter capacity (800 versus 500 gallons). That makes it our pick for households that need a lot of filtered water and want it as fast as possible. It adds a sediment prefilter, too, which the AQ-5200 lacks; this may extend the contaminant-filters’ higher flow in homes with sediment-rich water. That said, the AQ-5300+ model—with three liter-bottle-size filters—is much larger than the AQ-5200 and the A.O. Smith AO-US-200 but has the same recommended filter lifespan of six months. And it costs a bit more up front and for replacement filters (about $80 a set or $160 a year). So weigh its benefits against its higher cost.
Also great
Aquasana Claryum Direct Connect
The Claryum Direct Connect installs without drilling and delivers up to 1.5 gallons of filtered water per minute through your existing faucet.
Buying Options
*At the time of publishing, the price was $100.
Aquasana’s Claryum Direct Connect plumbs right into your existing faucet, making it a particularly attractive choice for renters (who may be forbidden from altering their place) and for people who can’t install a separate filter-faucet. It doesn’t even have to be mounted on the sink-cabinet wall—it can simply lie on its side. It offers the same 77 ANSI/NSF certifications as our other Aquasana and A. O. Smith picks do, and it can deliver up to 1.5 gallons per minute of filtered water, more than the others. The filter is rated for 784 gallons, or about six months of use. But it lacks a sediment prefilter, so if you have a sediment issue, it’s not a good choice, as it can clog. And it’s big—20½ by 4½ inches—so if your sink cabinet is small or crowded, it may not fit.
