
Water filters are a booming fear-based economy. But people have good reasons to be leery of their drinking water—chlorine, microplastics, PFAS everywhere, heavy metals in the groundwater, whatever else bothers me tomorrow.
But while most water filters seem to make many promises, only some back them up with independent third-party lab tests—something I’ve been sad to discover while testing and researching countertop, under-sink, and shower water filters. I’m downright relieved when I see the letters NSF or IAPMO, two of the main independent labs and certifying bodies based in the United States.
Those are the bodies that tested and certified filters from California-based Clearly Filtered, whose pitchers and under-sink systems I’ve been testing this month alongside a number of other brands. This is relevant, because Clearly is offering discounts on all of its filters right now. This includes a 10-percent-off blanket deal on all filters bought through its website, and 19 percent off if you enter your phone number to receive a promo code.
How Clearly Filtered Filters Work
Clearly Filtered is a bit different from one of its main competitors, ZeroWater, whose filters I’m also testing. ZeroWater removes pretty much all total dissolved solids, including minerals like calcium and magnesium, from water that has passed through its filter. This is an utterly thorough approach, but I’ve also noted it usually doesn’t taste quite as good as water that still has some mineral content.
Clearly Filtered’s water pitcher uses a carbon filter and other media to remove a number of substances, including free chlorine, PFAS and PFOA, and other heavy metals. But it doesn’t remove the mineral content or lower the total dissolved solids in your water at all. In part because of the activated carbon filter, my testing showed that the filter actually slightly increased the total dissolved solids. (Trace amounts of activated carbon are not a problem: if anything, some think it’s good for you.)
Clearly certifies its water pitcher to filter out chlorine and PFAS to international NSF specifications. The company also released lab results from IAPMO lab in New Jersey showing the reduction or near-elimination of hundreds of other contaminants that don’t all have corresponding international standards. (See all IAPMO lab results here.)
The resulting water still tastes pleasantly like the semi-soft water that comes out of my tap, minus nearly all of the chloramine (the chlorine compound used to disinfect my water in Portland, Oregon). The pitcher filter takes about 13 minutes to filter a half-gallon of water from the top reservoir into the bottom reservoir. But note that the priming process is a bit awkward, involving squeezing water through a somewhat fragile plastic bag to force it through the filter. This bag is then meant to be kept for future filters, or bought again for $15 if you lose or puncture it.
A 32-ounce stainless steel water bottle uses similar filtration technology as the pitcher but requires that you suck water through a filter attached to the washable drinking spout—a solution that lets you filter water out in the wild, wherever you may find it. You’ll have to suck pretty hard on the straw to pull water through the filter, but it’s a mostly elegant solution to instant water filtration—similar in concept to some backpacking filter straws but a lot more socially acceptable.
A Landlord-Friendly Undersink Solution
But the filtration system that I find most useful at home is Clearly Filtered’s three-stage under-sink system. In part, it solves a problem for me. A goodly percentage of under-sink water filter systems require some level of installation, space for a separate tap, or even integration with a faucet. As a renter, this makes them difficult for me to consider.
But the under-sink filter from Clearly installs in-line with the water line and works with your existing tap. It took me less than five minutes to install, without drilling a single hole or having to call my landlord. All I had to do was shut off my cold water line, unscrew the water line at the valve, and attach the water lines to the appropriate connections on the Clearly Filtered system.
It’s a more expensive system than the others from Clearly Filtered, but it does not require filling and refilling a pitcher that takes up space in my fridge or on my counter. It also lowered my water flow rate a little, but not enough to bother me. The lab-reported filtration levels for PFAS are also as good as I could expect, at or near 99 percent in most cases. My own chemical testing showed that the three-stage filter removed chloramine in my water system to undetectable levels. (The pitcher filter almost, but not quite, achieved this.)
Note that priming the three-stage filters does take at least 15 minutes of running out the tap, though I’d say I needed to run the water for a half hour before total dissolved solids went back down to normal levels. This mirrored my experience with the pitcher, which also required a few extra filtration cycles to prime fully.
Anyway, none of the Clearly Filtered systems are at the bottom of the market, price-wise. So the discounts are much appreciated, especially on the three-stage system, where percentage discounts pay off the most.
