4 Best Under-Sink Water Filters To Improve the Taste and Purity of Every Drop From Your Kitchen Faucet

Let’s be honest: Some household topics are nothing short of polarizing. Take toilet paper, for example. Do you put it on the roll with the tail hanging over or under? Same goes for paper towels. And what about butter? Do you refrigerate it or leave it on the counter so that it’s always perfectly spreadable? Then there’s the water debate—to use a filter or embrace tap? That is the question. And that’s what we’re here to discuss today.

When you think of water filters, your first thought is likely in-door refrigerator dispensers and pourable pitchers with filters. Of course, we’ve come a long way since both of those mechanisms came on the kitchen scene. After all, did you know that full-on under-sink water filters exist? Better still, did you know that adding one to your plumbing can drastically improve not only the flavor, but the overall quality, of the water you consume? If not—or even if you’re simply researching whether or not a filtration system is necessary in your home—keep scrolling for everything there is to know about under-sink water filters, including which are worth making room for in your cabinet.

What does an under-sink water filter do?

Water filters come in many shapes, sizes, and levels of effectiveness—hence why faucet attachments, in-door mechanisms, and standalone filtered pitchers exist. But if your goal is to streamline your filtered water, nothing compares to under-sink water filters, which remove contaminants before the water even comes out of the faucet.

“Under-sink water filters are a popular way to get healthier, better-tasting water because they typically remove more contaminants than pitcher filters and even bottled water,” explains Derek Mellencamp, water-filtration expert and general manager at Aquasana, a water-filter manufacturer. “By connecting directly to the water source at its point of use, under sink filters use your home’s water pressure to force tap water through ultra-dense filtration media, giving it the force and speed to remove more contaminants, faster than a gravity-based system like a pitcher filter.”

What to look for in an under-sink water filter

Not all under sink filters are created equally—but that’s not a bad thing. Instead, it means that there are plenty of options based on your home and family’s needs. 

Before looking for a filter, though, Mellencamp says it’s important to start by checking out your local water quality report. That way you can find out which, if any, contaminants are present in your area. “As part of the EPA’s Safe Drinking Water Act, all US water suppliers are required to send out an annual report that tells you where your water comes from and what’s in it,” he explains. “If you’re concerned about lead or any other toxins that may be specific to your home, you can also have your water tested by an independent lab.”

Once you determine which contaminants are at play, look for under-sink water filters with a Water Quality Association certification, says Steve Scheer, president of Brondell, a brand that produces water filters, among other household products. “You should look for efficiency, how many particulants it eliminates, and particularly for an RO [reverse osmosis] system, how much water is wasted.” (Mellencamp recommends also ensuring that your filtration system has been  independently tested and certified to NSF/ANSI or IAPMO standards to address the contaminants you’re concerned about.) 

According to Mellencamp, RO systems the ultimate under-water filter for maximum contaminant reduction. “They provide the most comprehensive protection and tackle even the more difficult substances like hexavalent chromium (think Erin Brockovich) and fluoride,” he says. “However, one downside of RO is that it typically also strips the beneficial minerals from water in the process.” Since you absorb most of your minerals through food, drinking demineralized water isn’t as big of deal as it may sound (you do it all the time if you’re not drinking natural spring or mineral water), but you can also remineralize yours by adding a pinch of Himalayan salt to your water.  

Specific systems aside, Mellencamp says that carbon filters are generally a good place to start with under-sink filtration. “Most filters on the market use carbon filtration technology to trap contaminants inside your filter, preventing them from flowing through your tap,” he says. Sold? Keep reading to uncover five highly-rated under-sink water filters.

Aquasana OptimH2O® Reverse Osmosis + Claryum® Filter — $250.00

“Aquasana’s OptimH2O® Reverse Osmosis + Claryum® Filter utilizes RO in conjunction with activated and catalytic carbon filters along with ion exchange to remove up to 99 percent of 88 contaminants,” Mellencamp says. “This system is unique because it adds beneficial minerals back into the water after it’s been filtered.”

Brondell Coral UC300 — $180.00

Scheer says that the UC300 is a great solution for larger households that want best-in-class water filtration with a small, convenient footprint.

“The UC300 includes an elegant, designer chrome faucet with an integrated LED filter change indicator that reminds you when it’s time to change the filter,” he says. “It is WQA Gold Seal Certified, and proven to remove 75 contaminants from your drinking water.”

HydroViv Under Sink Water Filter — $200.00

The coolest thing about the cult-favorite HydroViv Under Sink Water Filter (which normally costs $400 but is currently half off) is that it takes out the need to do your own local research. That’s because it automatically takes your location into consideration by analyzing your zip code upon order placement. What’s more, it’s known to be one of the easiest filters to set up because it hooks directly to the built-in faucet (rather than requiring a dedicated faucet) and only takes about 15 minutes to install.

Brondell Circle Under Counter Reverse Osmosis Filter System — $450.00

Here’s another high-quality RO system that doesn’t sacrifice water. “It utilizes patented new technology to eliminate back-pressure, making it up to 10-times more efficient than current conventional RO systems,” Scheer says. What’s more, Scheer points out that despite its powerful filtration abilities, it has a relatively small footprint compared to other systems. 

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