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Which under-sink water filters are best?

More people are concerned about the quality of their drinking water than ever before. Many buy bottled water, but more and more people concerned about the environment are buying water filtration systems instead. Now you can drink cleaner, better-tasting water because your filter system has removed the chemicals, impurities and sediment from it before it reaches you.

If you want an under-sink water filter system that installs in less than 30 minutes, take a look at the Filtrete Standard Under Sink Quick Change Water Filtration System 3US-AS01.

What to know before you buy an under-sink water filter

The purpose of an under-sink water filter system is to remove impurities, chemicals and odors to make your drinking water healthier and taste better.

Filtration types

Particulate filters: These are the filters that remove the tiny particles of rust, dirt and soil that find their way into your water supply. Many of these particles are visible to the naked eye, but not all. Fine mesh filters remove the contaminants.

Activated charcoal filters: By passing the water through charcoal, these filters remove chemicals such as mercury and lead by using a chemical bonding process. Charcoal filters are effective at removing odors and tastes.

Redox filtration: Oxidation reduction filtration systems use an electrochemical process to reduce contaminants such as chlorine and heavy metals including mercury and lead. Redox systems inhibit bacteria and reduce lime scale, mold and algae, too.

Ion-exchange filtration: Ion-exchange is the technology used in water softeners to dissolve bad ions and replace them with good ones. It differs from physical filtration processes by chemically changing the water. Ion-exchange systems get rid of calcium and magnesium.

Reverse-osmosis filtration: This process removes contaminants by forcing the water supply through a partially permeable membrane. Reverse-osmosis systems are effective at removing sediment and chlorine. Reverse-osmosis systems require a dedicated faucet.

What to look for in a quality under-sink water filter


Filters are designed to remove physical impurities from the water. Over time, sediment and chemicals accumulate, reducing the filter’s effectiveness at removing particulate matter. When the filter has absorbed all the impurities it can, it needs to be replaced.


Some under-sink water filter systems are made to install in the line from your water supply to your existing kitchen faucet. Other under-sink water filter systems require a separate faucet, so make sure you know which is which.

Kitchen faucet anatomy

Above the sink: Homeowners choose a kitchen faucet for its design, finish and ease of operation. All these are considerations above the sink. Included pieces are the body, the lever or knob(s), the spout, the aerator and sometimes a sprayer with a hose.

Below the sink: When you purchase an under-sink water filter system, you can install it yourself if you know how to use basic hand tools and can follow simple instructions. Check to see if you have the necessary space for the size of the under-sink water filter system and enough room to move freely while installing it.

How much you can expect to spend on an under-sink water filter

If you want a simple under-sink water filter system that removes basic impurities for up to six months, expect to pay $40 or $50. From $100-$150, you will find multi-stage filtration systems and more effective filters that remove more contaminants. From $200 upward, you will find under-sink water filter systems that filter out nearly everything.

Under-sink water filter FAQ

How do you know what contaminants are in your water?

DIY testing kit

A. You can check with your municipal water utility and see what they say, but the only way to know for certain is to test your water at the tap. You can do this with a DIY testing kit or you can hire a service professional.

How do you know if a water filter works with your water?

A. While shopping, consider only products that state on the package that their filter meets NSF (National Science Foundation) certification standards.

What’re the best under-sink water filters to buy?

Top under-sink water filter

Filtrete Standard Under Sink Quick Change Water Filtration System 3US-AS01

Filtrete Standard Under Sink Quick Change Water Filtration System 3US-AS01

What you need to know: The filters on this under-sink water filter system are very easy to change.

What you’ll love: This system filters water right at the sink without having to add another faucet. It maintains full water flow at 2.25 gallons per minute on your existing faucet. Standard, Advanced and Maximum replacement filters are certified effective for up to six months each. This compact unit filters sand, rust, sediment and chlorine so you can enjoy better-tasting water straight from the tap. It installs in less than 30 minutes.

What you should consider: It’s a small unit but requires a fair amount of space under your sink for you to be able to install it easily.

Where to buy: Sold by Amazon and The Home Depot

Top under-sink water filter for the money

Culligan US 1 E-Z Change Under-Sink Drinking Water Filtration System

Culligan US 1 E-Z Change Under-Sink Drinking Water Filtration System

What you need to know: This budget under-sink water filter system has its own dedicated faucet.

What you’ll love: The replacement filter cartridges for this E-Z Change filter system are changed by twisting them on and off. The double water shut-off allows you to change filter cartridges without spilling water under your sink. The 3,000-gallon filter cartridges require replacement only once a year.

What you should consider: The fittings included with this under-sink water filter system are for ½-inch hoses, so check the plumbing under your sink before you buy this or any system.

Where to buy: Sold by Amazon and The Home Depot

Worth checking out

APEC WFS-1000 Super Capacity Premium Quality 3-Stage Under-Sink Water Filter System

APEC WFS-1000 Super Capacity Premium Quality 3-Stage Under-Sink Water Filter System

What you need to know: The three-stage carbon block filter system is designed, engineered and assembled in the U.S.

What you’ll love: The first stage removes dust, particles and rust. The second stage removes chlorine, cloudiness, chemical tastes and odors. The third stage removes even more chemicals, tastes and odors. Filters need replacement only once a year. The premium quality faucet is made of lead-free spotless chrome, rotates 360 degrees and the sleek handle operates smoothly.

What you should consider: This system is pricey.

Where to buy: Sold by Amazon and The Home Depot

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David Allan Van writes for BestReviews. BestReviews has helped millions of consumers simplify their purchasing decisions, saving them time and money.

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