Best Under Sink Water Filters of 2021 and why it important

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Written By Oscar

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Drinking water straight from the tap might have been okay at some point in time, but today, more and more people are opting for water filtration systems to purify their drinking water. Rightly so, because who knows what impurities might be lurking in unfiltered tap water.

Choosing the right water filter for your home is clearly an important decision, because your health and well-being, along with your loved ones, depend on it. Therefore, we have gathered some of the best under sink water filters on the market, so you can choose the right one for yourself!   


APEC 5-stage water filter owing to the ease of installation, filtration efficiency, and stellar manufacturing plus assembly.
The APEC is designed to get rid of up to 99 percent impurities that may be present in tap water or hard water, as they say, so you end up with the very best quality water day in and day out, no wonder it is a best seller!


CuZn UC-2000 under counter water filter. With all the fixings of a durable filtration system with an economical price tag, it is quite the crowd favorite.
The CuZn water filter has ample capacity for providing a steady supply of clean drinking water. On top of that, it is incredibly lightweight and easy to work with.

Quick Comparison

Image Name Weight Capacity Price
APEC 5-Stage Top Tier Ultra Safe 25 pounds 50 gallons/day Check Price
CuZn UC-2000 8 pounds 10,000 gallons/year Check Price
APEC Top Tier Alkaline 3.11 pounds N/A Check Price
Big Berkey Gravity-Fed 7.45 pounds 2.25 gallons/minute Check Price
Frizzlife Under Sink Water Filter 4.2 pounds 2 gallons/minute Check Price
iSpring RCC7AK 4.05 pounds N/A Check Price
iSpring WSP-50 1 pound 20 gallons/minute Check Price
Big Berkey BK4X2 9.04 pounds 2.25 gallons Check Price
Watts Inline Water Filter 1.75 pounds 20,000 gallons total Check Price
Genuine Berkey 1.12 ounces N/A Check Price

Best Under Sink Water Filters 2021

1. APEC 5-Stage Top Tier

Kicking off this list with a bang, we have the APEC 5-stage water filter system. It has been manufactured and assembled in the United States, so quality assurance is pretty much spoken for.

It is designed to get rid of up to ninety-nine percent of contaminants found in water, including chlorine, arsenic, heavy metals, lead, fluoride, and the list just goes on as we get into the arena of bacteria and virus.

The APEC water filter has premium quality filters in place to treat tap water and keep an unlimited supply of clean and fresh-tasting water going at all times! With a smooth and silent operating mechanism, you will barely notice anything different once it is installed.

What’s great about the APEC water filter system is that it even surpasses bottled water in terms of quality and taste, not to mention the money you save. This filter system will last you a good long while with minimal maintenance.


  • FDA approved tubing and lead-free faucet
  • High-quality leak-free fittings
  • No extra lead detectors required
  • Easy to install
  • No noise and durable performance


  • Replacing parts might be slightly tricky
  • Changing filers is a bit time consuming

2. CuZn UC-2000

Coming in close at a very close second is the CuZn UC-2000 water filter. What’s great about the CuZn water filter is that it is quite simple to get the hang of. This, of course, extends to the installation process as well.

Basically, you can have it up and running in no time, think of it as a little DIY project! Besides, you do not have to deal with an additional third faucet for under-sink water filter installation as it can be connected directly to the cold-water line in your kitchen sink.

At most, you will need a wrench to tighten a few connections here and there. The CuZn works on a three-stage purification process that removes maximum impurities from the water, leaving you with crisp-tasting water all day, every day!


  • Lightweight and easy to install
  • No additional equipment needed to install
  • Can be connected to water line directly
  • Based on three-stage filtration to remove impurities
  • Does not remove healthy minerals from water


  • Cannot be used to deal with hard water problems
  • Can only be used with municipal water, not well water  


Yes, you read the title right, another APEC water filter system has managed to grab one of the top spots on our list. A step up from its counterpart above, the filter works on a six-stage mechanism to remove all sorts of viruses, bacteria, and harmful chemicals from water.

Besides being manufactured and assembled in the United States, it also has food-grade calcium cartridges from the US to maintain the pH of your drinking water. The cherry on top is that it even adds healthy calcium minerals to the water for enhanced taste.

The system itself is quite smooth while in use, and you will barely notice any noise. All parts of the filter are included and guarantee a durable filtration system in the long haul! Also, you don’t have to worry about extra equipment or leak seals because the system is already entirely leak-proof!


  • Improved alkalinity and taste of water by adding calcium minerals
  • Long-lasting performance
  • Leak-proof fittings, no leak detector needed
  • High quality, premium filter, and FDA-approved tubing


  • A few reports regarding the loss of pressure
  • Installation may be tricky for some systems

4. Big Berkey

As the title suggests, the Big Berkey Gravity-fed under-sink water filter system UK is truly a force to be reckoned with. With a total capacity of 2.25 gallons, it can hold enough purified water for up to four people every day. What’s more, is that it is portable, so installation is a breeze, and you can pretty much take it anywhere.

In this way, the Big Berkey gives you access to clean and crisp water at all times. In terms of filtration, it is efficient by more than ninety-nine percent. It will remove all kinds of harmful impurities from tap water, including but not limited to bacteria, inorganic materials, heavy metals, pharmaceutical drug traces, and so much more.

The Big Berkey is definitely here to stay, and with its long-lasting performance, you won’t find yourself running around trying to find replacement parts any time soon. The cherry on top is the money you get to save by having your own filtration system and not having to rely on bottled water.


  • No additional tools required
  • Does not require any plumbing or electricity connections
  • Filtration elements can last up to 6000 gallons before needing replacement
  • Lightweight, portable – easy to travel with


  • Might need frequent priming
  • Few complained of recalled components and/or reconditioned models

5. Frizzlife

On the surface, Frizzlife may seem like more of a hair styling product, but trust us, it is an actual water filter system with a slightly more edgy name! First things first, the Frizzlife water filter guarantees up to ninety-nine complete removal of any lead-based impurities from drinking water. 

It is based on a two-stage filtration mechanism that is extremely precise and leaves your regular tap water with added nutrients and minerals, and an overall better taste. It is effortless to install as you can connect it to your cold-water line directly, and it will be good to go!

The best part is that you don’t need any other fittings for plumbing etc. You can rest assured as the feeding pressure is quite intense, and the filter has ample capacity, so you will have fresh running water at all times!


  • Economical fittings and long-lasting performance
  • Automatic built-in shut-off valve to make replacements easier
  • Easy installation, no extra tools required
  • Removes up to 99 perfect impurities from water


  • There may be some leaking in the cartridge
  • Is not NSF Certified

6. iSpring

Another contender for the best water filter system on the market is the iSpring RCC7AK under sink water filter system. It is based on a six-stage working mechanism that purifies your drinking by up to ninety-percent.

It removes all sorts of bacteria, viruses, heavy metal traces, and chemicals such as lead and chlorine to enhance the pH of water, restore alkalinity, and provide you fresh-tasting water all day long.

Also, it is excellent for resolving hard water issues and re-adds healthy minerals to water via a smooth reverse osmosis mechanism. Everything you need to install the filter is already included in the package, making installation a breeze compared to traditional filter systems.


  • Leak-proof tubing
  • No extra fittings required
  • Premium quality water – better than bottled water
  • Easy to install
  • Restores healthy minerals and alkalinity


  • Hardware might need regular maintenance
  • Might need leak detectors for specific systems

7. iSpring WSP-50

Following another iSpring filter, we have the WSP-50 reusable sediment water filter that is designed to purify your drinking water from any kind of dirt, sand, rust, sediment, and any larger particles that end up getting through.

You will find that it is quite efficient in terms of performance, and the reusable filter does an excellent job of regulating the flow of purified water. The brass and stainless-steel manufacturing ensures that the filter remains in stellar condition for a good year or two before needing to be replaced.


  • Premium quality filters – do not get clogged easily
  • Reusable filter elements
  • Durable up to two years
  • Easy to install
  • Removes impurities such as sediment, dirt, rust, and sand


  • May require leak detector
  • The casing needs to be removed to clean the filter

8. Big Berkey BK4X2

Another filter from the Big Berkey family of filters is the BK4X2, manufactured from stainless steel all over. It contains two Big Berkey filters and two additional fluoride elements, and has a capacity of 2.25 gallons, making it one of the best under-sink water filter fluoride systems.

In short, it is enough to keep a steady supply of clean drinking water for anywhere between four to sixteen people in a household. Each purification element has a lifespan of about 3000 gallons, so you should be good to go for 6000 gallons!


  • Simple attachments – easy to install
  • The expected lifespan of 6000 gallons for a two-element filter system
  • Supplies purified water for up to 16 individuals


  • Leak detectors might be needed
  • May need to be regularly cleaned which may be inconvenient

9. Watts Inline

The Watts Inline water filter is perhaps one of the most versatile water filter systems on our list. It can be used in ice-makers, refrigerators, boats, campers, and water coolers! It is also portable so you can take it along on road trips and camping adventures!

It is straightforward to install and does not require any extra fittings or connections. You will not need to keep up with any maintenance for up to six months.

It is guaranteed to get rid of the most harmful chemicals while simultaneously enhancing the pH and taste of the water!


  • Reduces odor and contaminants for hard water
  • Lasts for up to 20,000 gallons of water in total
  • Versatile in terms of usage


  • Filters need to replaced frequently
  • Plastic cartridges may break down easily

10. Genuine Berkey

To top it all off, we have the Genuine Berkey Stainless Steel Spigot, the epitome of sleek and simplistic designs that get the job done right! With a modern design, it offers a brand-new twist on a water filter for sink faucet over those traditional filter systems of yore.

The stainless steel makes it so it is quite easy to clean and will be spotless once you are done. In terms of installation, the process is pretty direct, so you will not have to go through much hassle to get the filter up and running!


  • Installation takes minimal time and effort
  • Stainless steel material – easy to clean inside out
  • Simplistic and direct fit design


  • May have some quality control issues for individual components
  • Some components may be too sharp for direct handling   

4 Things to Consider Before Buying Under Sink Water Filter

When it comes to the well-being of your family, we are sure that you will not settle for anything less than perfect. Ensuring a steady supply of clean water is, of course, a given in this regard as well.

If you are particular about your drinking water, then it might be time to get your hands on an under-sink water filter. However, before you go out to buy your very own screen, there are a couple of things you need to keep in mind.

Although this is true for any new product, the stakes are particularly high with this one because it has a direct impact on your health and that of your loved ones.

Luckily, we have just the little buyer’s guide that will ensure that you end up with the best under-sink water filter that the market has to offer!

Water Pressure/Flow Rate

Water pressure is the rate at which water flows out of the filter at a particular instant. Good water pressure means that you do not have to wait too long to fill up your glass or bottle.

Under-sink water filters and underwater filter systems, in general, have much better water pressure as compared to traditional water filters.

However, this means that water is not contained in the filter for long, which means that some impurities may be left unfiltered in the water.

This might be a significant problem if you reside in an area where the water supply is highly contaminated. Therefore, this is a very important factor to consider before buying a water filter.

The Capacity of Filter Element

The function of the filter elements refers to the degree to which the water is purified from impurities. The filter you want to buy should rid regular tap water of more than 99% impurities, to make it safe for drinking.

This largely depends on the type and quality of cartridge that your filter uses. Another thing to consider is whether the filter is designed to remove a particular type of contaminant found in your municipal water supply.

Checking for specific contaminants is crucial because even filters that perform well overall may leave some impurities behind, which may be detrimental to your health. To test this, you can perform a water quality testing kit at home to get an idea of the kind of contaminants you are up against.

Ease of Installing/Replacing Filter

Out of the types of water filters out there, one thing they all have in common is that they are all reasonably easy to install. The quicker the installation, the lesser the risk of damaging the filter during the process.

In doing so, you should also check whether you can do it yourself, so you don’t have to hire somebody else to do it. This will save you time and money in the long run, which is always a win-win!

Lifespan of Cartridge

Most filter cartridges last up to six months without the need for a replacement. However, some are built to last even longer and can go up to five whole years without a change.

The lifespan of a cartridge depends entirely on the quality of the filter element, but these cartridges are typically tested with municipal water.

If your water supply is different, then it might be best to use a water filter test kit before settling on any one water filter. 


At the end of the day, it is always best to have done your research well beforehand so you have a clear idea of what you want before you actually go out looking for a particular product. Water filters are no different.

However, with these few factors in mind, we’re confident that you will have no trouble locating the right product for yourself!  

Frequently Asked Questions

What is an under-sink water filter?

An under-sink water filter is a device that can be used to purify water from certain impurities that may be found in tap water. These include various types of bacteria, viruses, heavy metals, pharmaceutical drug traces, and other harmful chemicals such as lead and chlorine.

What is an under-sink water filter?

An under-sink water filter is a device that can be used to purify water from certain impurities that may be found in tap water. These include various types of bacteria, viruses, heavy metals, pharmaceutical drug traces, and other harmful chemicals such as lead and chlorine.

Besides, it maintains the pH and alkalinity of tap water, leaving a much better taste. It is excellent if you are experiencing hard water issues with your local municipal water supply.

Although it strips water from impurities, a water filter does re-add healthy minerals in the water that bode well for the overall quality of your drinking water.

How to install an under-sink water filter?

Some of the best under-sink water filters come with all the additional fixings needed to install the filter correctly, along with detailed instruction manuals for the specific model and design.

For more information on installation and the tools needed, you can also lookup videos online. However, for the most part, the process is pretty simple, and you do need much extra equipment.   

How to use an under-sink water filter?

Under-sink water filters pretty much work on the back end of things, and you will not need to actively keep track of anything once it is installed. This is because it re-works the water supply and keeps it free from impurities so that you can drink directly from the tap without having to worry about anything!

Do under-sink water filters remove chlorine from tap water?

Yes, as mentioned above, under-sink filters can remove all kinds of harmful chemicals from tap water, chlorine being very much one of them.

Besides, it can also remove lead, sand, dirt, rust, and sediment residue from your local water supply to keep your clean supply of water going day in and day out.

Where can I get a good under-sink water filter? 

There are specialized stores in the market that sell under-sink water filters. You can either visit those in person or look for suitable water filtration systems online.

Even if you do plan on buying a water filter in person, it is recommended that you streamline a couple of options online and compare several different products to have a clear idea of what you want.

Is one under-sink water filter enough for a big family?

One of the many benefits of under-sink water filters is that most traditional water filters have ample capacity for supplying clean drinking water to a family of four at least.

This means that an under-sink water filter is an ideal choice for most families. However, there are other models out there that can house families comprising up to sixteen people.

What is the best under-sink water filter?

Now the answer to this question pretty much depends on each individual case. For instance, the quality of tap water in your particular area, size of your family, fitting of the filter system. However, some of the strongest contenders include the APEC, CuZn, and iSpring water filters.

Is it easy to clean an under-sink water filter?

Most under-sink water filters have pretty durable filtration elements. One filtration element will be useful to go for at least 3000 gallons or so on average. So, you can expect about 6000 gallons for a dual element system.

However, the specifics for your particular may be different, so you might want to check and make sure you are getting what you need precisely.

Why are some under-sink water filters more expensive than others? 

The cost of a water filter depends on several factors such as the size of the filter, the company, the general maintenance, and upkeep needed to keep the filter going. Therefore, the price may vary quite significantly from one product to another.

How long does an under-sink water filter last?

Depending on the type of filter, the size, and the quality of the filter element, an under-sink should be good to go for a good many years. You will need to replace the filter every few months or so, but that is merely a part of the general upkeep to keep the filter working efficiently.

Will a water filter take care of hard water issues?

Yes, most under-sink water filters do resolve hard water issues. However, not all water filters are designed with water softening properties. Therefore, we suggest that you read the fine print for this one before making a decision.

Does a water filter gets rid of cloudy water?

Some people complain about ‘cloudy’ water that comes straight from the tap. This might be due to some residue or sediment in the pipes. Having an under-sink water filter should remedy this and give you clear, fresh-tasting water.

Is an under-sink water filter portable?

There are quite a few water filters out there that are portable and can be taken along on camping trips and road trips, which comes in quite handy because you have access to clean drinking water at all times. 

Some larger water filters, although not portable in the traditional sense, can be disconnected and taken to another house if you are moving and want to keep the same filtration system.


With such a vast range of water filters at your disposal, we hope you will find it easier to make a decision. As you can see, there is a lot to consider.

However, knowing your own preferences and what each filter has to offer should make the ordeal a whole lot easier! For any further queries, feel free to contact us via email!

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Buried in his toolshed, pulling an appliance or two apart, is where you’re likely to find Oscar on most days. Ever since his brother introduced him to the world of tinkering and repairing, Oscar has been obsessed with his craft and especially loves taking appliances around the house apart and then putting them back together. He’s definitely the quirkiest among the team, and loves explaining in detail how one appliance is different from the other and how each of them works (after having taken them apart and satisfied his curiosity of course).

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