5 Best Under-Sink Water Filters for Clean H2O
This collection of the best under-sink water filters will have you and your family enjoying clean, clear and contaminant-free water in no time.
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Instead of consuming countless single-use plastic bottles or constantly refilling a pitcher filter, an under-sink water filter could be a convenient alternative. These systems are hidden in the cabinet below your sink and connect to your existing water supply hose, allowing you to enjoy clear, contaminant-free water right out of your faucet.
The best under-sink water filters get the job done with minimal maintenance required, and we’ve included a range of types and sizes to choose from. Whether you’re looking for a high-end option for your home faucet or a compact version for a bathroom or RV, you’ll find one that fits your needs.
5 Best Under-Sink Water Filters
- Best Overall: Aquasana Two-Stage Under-Sink Water Filtration System
- Best Budget: Culligan EZ-Change Under-Sink Filtration System
- Best Reverse Osmosis: Apec Water Systems ROES-50
- Best Ultrafiltration: Waterdrop 15UA-UF Ultra Filtration System
- Best Tankless Reverse Osmosis: Waterdrop G3P600 Reverse Osmosis System
Best Overall Under-Sink Water Filter
Aquasana Two-Stage Under-Sink Water Filtration System
This Aquasana filter uses two types of carbon filters and an ion-exchange system to remove up to 99% of contaminants, allowing beneficial minerals to pass through and making it an easy choice for the best under-sink water filter. It’s also efficient enough to process half a gallon of water every minute, costing just $0.10 per gallon. The filters are simple to replace, and their compact size makes this filter convenient to fit inside a wide range of kitchen cabinet sizes.
- Removes up to 99% of 77 contaminants
- Includes kitchen faucet
- Easy to install
- Comes in multiple finishes
- Certified to National Science Foundation (NSF) Standards 42, 53 + 401 and P473
- Filters must be replaced every six months
Best Budget Under-Sink Water Filter
Culligan EZ-Change Under-Sink Filtration System
This Culligan model provides effective filtration at a price much lower than similar under-sink options. For a wallet-friendly price, you get an RC-EZ-1 cartridge that’s effective enough to prevent Class III particulates from infiltrating your drinking water, improving the overall taste. This cartridge has a lifespan of up to 3,000 gallons and is compatible with a range of Culligan replacement cartridges, from EZ-1 to EZ-4. We also love the dedicated dispenser faucet, which, depending on your sink setup, can fit over an existing sprayer or soap dispenser hole.
- Affordable price
- Filter lasts up to 12 months or 3,000 gallons
- Includes all installation hardware
- Meets American National Standards Institute (ANSI) Standard 42 certification
- Relatively low flow rate of .5 GPM
Best Reverse Osmosis Under-Sink Water Filter
Apec Water Systems ROES-50
This Apec system utilizes five stages of filtration, including a reverse osmosis membrane and dual coconut carbon blocks, to remove up to 99% of all contaminants in your drinking water. It also includes a brushed nickel faucet, making it a smart option for homeowners wanting to replace an outdated model. Apec does an excellent job of setting you up for success when it comes to installation, too, and includes two housing wrenches for the filter and membrane components, as well as a link to step-by-step instructional videos.
- Multi-stage filtration
- Easy to install
- 2-year warranty
- Improves water taste
- Removes up to 99% of impurities
- Uses more water than other filter types
Best Ultrafiltration Under-Sink Water Filter
Waterdrop 15UA-UF Ultra Filtration System
Thanks to a specialized membrane and multiple filtration media, like activated carbon, this Waterdrop system provides a filtration accuracy of 0.01 microns. The direct-connect fittings make installation a breeze, dual gaskets prevent leaks, and a converter works on both 1/2- and 3/8-inch water lines. We’re most impressed by the lifespan of this filter, which has a max service life of two years or 16,000 gallons. The compact size is convenient for tighter spaces, making it a quality RV water filter while still powerful enough to process 0.75 gallons per minute.
- Effective against extremely fine contaminants
- Filter lasts up to two years or 16,000 gallons
- Retains beneficial minerals
- Simple installation
- Doesn’t include a dispenser or faucet
Best Tankless Reverse Osmosis Under-Sink Water Filter
Waterdrop G3P600 Reverse Osmosis System
Unlike most reverse osmosis systems that require a separate pressure tank to store filtered water for drinking, this tankless Waterdrop model uses an electric pump to provide water as needed. This allows you to experience the benefits of reverse osmosis without needing a lot of extra space—though it does require an accessible electrical outlet. You’re also getting a smart display faucet, which gives you a real-time readout of the filter status, as well as the quality of the water you’re drinking.
- Requires 70% less space than tanked systems
- Sleek design
- Simple to maintain
- Three filters are included with purchase
- NSF/ANSI 58 + 372 certified
- Requires an electrical outlet
What to Consider When Buying an Under-Sink Water Filter
In order to select the best under-sink water filter for you, consider the different types of filtration available. There are many variations of water filters, from basic carbon options that work by binding to contaminants as the water flows through to reverse osmosis units that force water through a semipermeable membrane that captures even smaller compounds and impurities. If you have any specific contaminants you want to filter out or if your priority is improved taste, ensure your filter is certified to perform those tasks.
If you have a large family or use a lot of water for cooking and drinking, make sure you take the flow rate into account as well. This metric should clearly state gallons per minute (GPM). You should also ensure the unit you’re considering will fit under your sink and, if you plan to install it yourself, doesn’t require any DIY methods that are outside your expertise.
How We Found the Best Under-Sink Water Filters
As shopping experts, our only job is to help you find a winning product. We start with the research and reporting basics—what products are made of, what they look like, and how much they cost—to ensure that we’re only recommending the buys that are worth your time and money. Then, we research the features that speak to the product’s quality, taking advice from industry insiders and subject-matter experts on what makes a product a smart value (or worthy of a splurge). Finally, we do the work of combing through user reviews to see how real people interact with the product, and if it stands up to the test.
Are under-sink water filters worth it?
If you consume more than a few gallons of tap water a day and you can afford one, an under-sink water filter is probably worth it. Once installed, they do most of the work and, until it’s time to replace the filter, are generally low-maintenance. On the other hand, if you don’t drink that much water or if you’re a renter, a pitcher or faucet-mounted filter could be a more practical option.
How long do under-sink water filters last?
The lifespan of an under-sink water filter cartridge can vary from six months to multiple years, depending on the size of the unit, as well as the quantity of water being processed.
How do you change an under-sink water filter?
The best under-sink water filters make changing out their filters and cartridges a straightforward process, but some are easier than others. Multi-stage units may require you to shut off the water supply and use a housing wrench to access the spent cartridge. More basic designs allow you to simply untwist the exposed cartridge and twist on a new one in a few seconds.
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