The Best Under Sink Water Filter – Complete Buying Guide & Reviews

​Clean, safe, great-tasting water is essential to any home. Though most municipal tap water in the United States is safe and healthy to drink, there’s always a chance that it can be contaminated, and it doesn’t always taste good. 

One of the best ways to make the most of your tap water is by using an under sink water filter. Water filters eliminate the need for bottled water, which is a huge waste of money and plastic. Under the sink, filters are a great alternative to countertop filter systems or filtering pitchers because they don’t waste any valuable counter or fridge space.

Under sink water filters are now more effective and efficient than ever. Until recently, some contaminants were only able to be removed with reverse osmosis systems that were expensive and wasteful. New technology in the cartridge filters used by under-sink water purifiers allows them to reduce more contaminants than previously possible.

Under sink water filters are now great at removing the sediment, arsenic, heavy metals, chlorine, nitrates, and bacteria that could be in your water, in addition to improving its taste and odor.

​How do They Work?

There are two main types of under sink water filters: simple under sink filters and conventional under sink systems. Both are great options, so choose the one that is the best fit for your home and budget.

Simple Under Sink Filter:

These water filters are affordable and easy to install. When they are installed under your sink, all the cold water supply passes through the filter before it comes out from your regular faucet. Once installed, simple under sink water filters are also incredibly easy to use–you don’t even need to remember to use it, your cold water will be automatically filtered whenever you turn on the tap.

In addition to their convenient simplicity, these filters are also relatively cheap, easy to install, and they require no additional faucet or modification to your counters. But keep in mind that because more water flows through simple under sink water systems, you will need to change the filters more often. All in all, they’re a great option for those looking for an easy and affordable water filter.

Conventional Under Sink Filter:

The other common type of under sink water filters are called conventional under sink filters. They’ve been around much longer than the simple filter systems, but don’t count them out as outdated. Conventional under sink filters are still an excellent choice for someone looking for a water filter that will send drinking water straight from the tap to glass. They are more complicated to install because they require a separate tap for the filtered water.

​After diverting the water from the main cold water pipe, it passes through the filter and comes out of a separate faucet that’s been mounted to the sink. Only water through that faucet is filtered, leaving your regular faucet unfiltered as normal. Because less water is filtered through the system, the filters will last much longer. Also, because the reduced flow slows things down, your water will spend more time in passing through the filter, making it even cleaner. The obvious con to this system is that it can be a pain to install, and you’ll probably have to drill a hole in your counter or sink for the new faucet. Conventional under sink systems are also much slower, so if you plan on filtering a lot of water in a short time or using filtered water for cooking, a simple system is probably better.

All Around Best Under Sink Water Filter:

CuZn UC-200 Under Counter Water Filter – 50K Ultra High Capacity

The CuZn UC-200 Under Counter Water Filter is one of the most popular under sink filtration systems on the market, and it’s pretty easy to see why. The benefits of this option kick in before you ever use it to filter your water because it’s one of the easiest products to install–it only takes about 5 minutes. Unlike most other under sink water filters that use a conventional system (see above), the CuZn UC-200 uses a simple water filter system that doesn’t require an additional faucet or any modifications to your sink or counter. To make installation even easier, CuZn offers free, easy to follow video instructions. Find them on their website or by searching “UC-200 Water Filter Install” on YouTube.

Better yet, once you’ve installed one of these, it will be good to go for years! The CuZn UC-200 has a lifetime capacity of about 50,000 gallons of filtered water, which lasts most households around five years. That’s a definite convenience upgrade from other filters that need to be changed every six months, and your wallet will thank you too.

This filter uses a three-stage filtration system including micro sediment membranes and a patented combination of KDF-55 filtration and virgin acid-washed catalytic coconut shell carbon filtration. Translation? This winning combination will reduce a wide variety of organic and inorganic contaminants like chlorine, water-soluble heavy metals (lead, mercury, chromium VI, cadmium, etc.), herbicides, pesticides, sediment, algae, molds, bad taste, and odors. It does all that without removing the minerals that do have health benefits, like fluoride, calcium, and magnesium. It’s bacteriostatic system also eliminates the risk of mold and bacteria sometimes found in other systems that rely on carbon filters.

One thing to note: the CuZn UC-200 is a bit bigger than many other filters, which could be a problem if you don’t have much space under your sink, so make sure to check the dimensions first. Otherwise, everything about this under sink filtration system is great.

Facts and features:

  • 4 x 4 x 15.5 inches
  • Product weight: 8 pounds
  • Lifetime capacity of 50,000 gallons or 5 years
  • 5-year pro-rated warranty and a 90-day satisfaction guarantee
  • Designed for use with municipal water, not private well water
  • Easy installation: no additional faucet
  • 3 stage filtration process includes Micro Sediment Membranes, KDF-55 & Coconut Shell Carbon
  • Purifies the water without removing minerals with health benefits
  • Compatible with DPD#1 Chlorine Test Strips
  • A bacteriostatic filtration system is not susceptible to mold or bacteria growth

Best Conventional Under Sink Water Filter:

Aquasana 3-Stage Under Sink Water Filter System with Brushed Nickel Faucet

If you want a water filter with a separate faucet, this is an excellent choice. The Aquasana 3-Stage Under Sink Water Filter System is another great choice. It is a high-performance filter that provides great-tasting healthy water. This under sink filter utilizes a 3 stage drinking water system, delivering superior water filtration and a 600-gallon capacity. The first filter is a pre-filter designed to reduce clogging or low water pressure by catching any sediment. This makes it 25% faster than other conventional filters, with a flow rate of half a gallon per minute.

The next two filters use Claryum filtration technology to remove over 97% of chlorine, lead, asbestos, herbicides, pesticides and over 60 other common water contaminants. The Aquasana also comes with a performance indicating advice that lets you know exactly when you need to change your filters, for added peace of mind.

It isn’t as easy to install as the CuZn UC-200 or other simple under sink filtration systems, but once you’ve completed installation, changing the filters is a breeze. A quick quarter turn will remove the old filter, and then simply twist on the new one. You don’t need to disconnect any hoses or water lines. The filters also have minimal disposable plastic parts, making the Aquasana a more eco-friendly option.

This filter comes with a great chrome faucet that will make a beautiful addition to any kitchen. If the brushed nickel finish isn’t your style, there are other finish options too!

Facts and features:

  • 12 x 4.2 x 9 inches
  • Product weight: 6 pounds
  • 1 Lithium Metal batteries required (included)
  • Battery life of 1590 hours
  • Flow rate: 0.5 GPM
  • Spout height: 7 inches
  • Spout reach: 4.5 inches
  • One year warranty
  • Provides better tasting food and beverages
  • Removes up to 99% of 77 contaminants including lead, mercury, pesticides, pharmaceuticals, and more
  • No water is wasted, and no contaminants are added back into your water
  • Capacity of 600 gallons ($.09 per gallon)
  • Stylish designer all metal faucet included to match your kitchen decor is 100% lead free
  • No plumber needed for installation, includes first set of filters and all parts required

Best Budget Under Sink Water Filter:

Woder 10K Ultra High Capacity Direct Connect Water Filtration System — Under Sink, Premium Class

If you’re looking to spend less than $100 on an under sink water filter, this one is the way to go. Costing less than $70 and lasting up to 3 years, the Woder 10K High Capacity Direct Connect Water Filtration System offers excellent value for the money. This filter uses unique technology to remove over 99.99% of contaminants while leaving in essential minerals which are vital to your health, including calcium, potassium, sodium, phosphorus, chloride, and magnesium. Woder filters eliminate lead, heavy metals, chlorine, chromium 6, mercury, volatile organic compounds, carcinogens, and other contaminants in addition to odors and bad tastes.

Not only is it effective, but the Woder 10K is also easy to install and maintain. Everything you need to install it is included, and it requires no expert skills to install in a short time. After installation, it will last for around three years with no adjustment or maintenance, filtering up to 10,000 gallons in that time. It’s also really compact, making it a great option for small apartments, bathroom sinks, and offices.

Facts and features:

  • 12 x 2.5 x 2.5 inches
  • Product weight: 1.9 pounds
  • Capacity: 10,000 gallons
  • Flow rate: 3 gallons per minute
  • Hose length: 75 centimeters
  • Water temperature range 37-122 degrees F
  • Eliminates 99.9% of contaminants like lead, heavy metals, and chlorine
  • Easy installation: comes as a complete assembled kit
  • Includes: Filter body, inlet hose (3/8 compression by 1/4 standard pipe thread), outlet hose (3/8 compression by 1/4 standard pipe), clip, and screw
  • Allows essential minerals natural in water to pass through unaffected
  • Will last for up to 10,000 gallons, or roughly three years of use! Enjoy a strong flow and easy stream from the world’s best under sink filtered water.
  • Built with NSF approved materials (NSF61) tested by independent laboratories to NSF/ANSI 42 Protocols
  • Money-back guarantee

​Best High-End Under Sink Water Filter

APEC Top Tier 5-Stage

If you are out to find a top of the line product without much concern for the budget, the APEC Top Tier has  a significant amount of features that shade all others. While it is priced double compered to the competition, it has a significantly greater capacity. It is not hard to maintain and the process of reverse osmosis will clean all the impurities from the water without influencing the oligominerals that should be inside and which give the water the ’’fresh taste’’.

There is a reason why this product is marketed this way, as it gives all the features of prior products, which added quality of the materials, durability, and capacity. There are no actual downside for this product as it is, but the price tag might be over budget for many households, and if you don’t really need all the bells and whistles, you may consider one from above.

Facts and features:

  • Made in the USA
  • Good materials
  • Good design
  • Easy installation
  • Removes 99% of impurities, both organic and non-organic
  • Premium long lasting filters
  • 2 year warranty

​Things to Consider:


Most under sink water filter systems require new filters every six months or so, but there are some that last up to 5 years. This partially depends on the type of system you install: simple under sink water filtration systems can often last for a shorter time because more water passes through them.

Sometimes the longer lasting ones are more expensive, but usually, they’re well worth the cost. In addition to reducing replacement filter costs, a filter’s longevity may be an indication of its quality. Because most filter cartridges work in pretty much the same way if one is capable of filtering significantly more water, that probably means it’s built better and made of high-quality materials you can trust.

Keep in mind that the quality of the water being filtered can also impact the lifespan of your filter, so if your municipal water isn’t great, expect to change your filters more often.

Filtering Needs:

Some water filters are better at removing some types of contaminants than others. Most under sink filtration systems will remove common toxins like lead, chlorine, and pesticides, but not all of them will efficiently filter other contaminants like algae, molds, volatile organic compounds, or carcinogens.

Before deciding on a water filter, we recommend using a home water quality testing kit that will let you know which contaminants are present in your water source. With that information, you should look for a filter that efficiently removes those specific contaminants.

Another thing to consider is what minerals and compounds you don’t want to filter out of your water. Some filters, especially reverse osmosis systems, remove all minerals from your water supply, even the ones that have health benefits. If you want your water to contain healthy minerals like fluoride, calcium, potassium, sodium, phosphorus, chloride, and magnesium, look for a filtration system that allows those to pass through.

Ease of Installation, Use, and Filter Change:

Some under sink water filters require professional installation, and others you can install yourself in just a few minutes. The last thing you want to do is damage your plumbing while trying to DIY install a water filter to save money, and then have to spend significantly more on repairs. Avoid that headache by choosing one that’s easy to install (or hiring a pro, to begin with).

Also consider how often you will need to change the filters, and how difficult and time consuming that will be. Some filters have cartridges that twist off easily in seconds, but others require a complete reinstallation when they need to be replaced. Depending on the lifespan of the cartridges, that may or may not be worth the hassle.

Water Pressure:

Approximately nobody wants to stand at the kitchen sink for what feels like hours to fill one pot, pitcher, or even glass of water. If you don’t have great water pressure, to begin with, it’s especially important to choose an efficient water filter. Simple under sink water filters are usually better for this than conventional ones, but not always. Before buying a filter, see if you can find the flow rate first.

Wrap Up

All of these filters are great choices, but the CuZn UC-200is probably going to be the best fit for most people because of its longevity, effectiveness, and efficiency. If any of the aforementioned under sink water filters are the right choice for your home, check out the links above. Stay hydrated, everybody!

About Gus Donaldson

I built houses for over 30 years and recently retired. I've made lots of mistakes and hopefully teach you not to make the same ones. I still love to build and have a garage workshop that I use for hobby projects like the walnut bookshelf I made for my wife. I like to write and let people know that working with your hands and tools does not need to be intimidating.

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