Are you looking for a quality water filter that connects to the plumbing under the sink but isn't a reverse osmosis system?


My aim in this post is to help you make the right choice the first time. (Unlike moi, who bought her first under the counter water filter after doing zero research. Big mistake!)

I spent many hours gathering data and consumer feedback for this guide to the best under sink water filters in the low to mid price range.

First there's a table comparing the five models. You can do a quick check of prices from there.

Next is information about how these filters work and tips for choosing the right one for your needs.

Then you'll find in depth information about each individual water filter followed by my final verdict.

Spoiler Alert! ----> My Number One pick is the Clearly Filtered 3-Stage Under-the-Sink Filter System.  You can check out the price and availability right now at Amazon or at Clearly Filtered.

In a hurry and don't want to read the whole article? Use the quick navigation below to skip to whatever interests you the most.

Comparison Table: Best Under Sink Water Filters

**This table is best viewed in horizontal orientation on mobile devices.**


Filter Life

Reduces Lead?

Reduces Fluoride?

Separate Faucet?


Check Price

Clearly Filtered 3-Stage

Clearly Filtered 3-stage under sink water filter

1 year




1 year



CuZn UC-200 water filter

5 years or 50,000 gallons




1 year

Woder 10K-Gen3-DC

Woder 10K-Gen3-DC water filter

3 years or 10,000 gal




1 year

iSpring CU-A4

iSpring CU-A4 water filter system

6 months  or  1,100 gal




1 year


APEC WFS-1000 water filter system

1 year  or 1,500 gal




1 year

How do under sink water filters work?

As the name implies, an under sink water filter is installed in the space underneath your kitchen sink.

diagram showing under sink water filter

Under Sink Water Filter with Dedicated Faucet 

Most models come with a mounting bracket so you can attach them to the cabinet wall. You'll also get tubing and fittings to hook it up to your cold water line.

The cold water is diverted through the filter and out the faucet. It works totally by water pressure and doesn't use electricity at all.

Some models have a dedicated faucet that you also have to install. Otherwise, the water  will come out through the existing sink faucet.

What are the advantages of under sink water filters?

  • Saves Countertop Space - These filters go completely under the sink so you don't lose one square inch of your precious countertop space.
  • Filtered Water on Demand - Unlike countertop gravity filters and pitcher filters, there's no waiting for water to drip through. Just turn on the tap and get filtered water instantly.
  • Low Maintenance - The only maintenance you'll need to do is changing out the filter element(s) every now and then. Most models have a filter life of at least one year, so you won't have to do it very often.
  • Effective - Whatever contaminants you're concerned about, you can find an under sink filter to take care of them. Not all brands are the same, though, so be careful.
  • Variety of Options - There are plenty of types of under sink water filter systems to choose from to meet your specific needs. Some can be used in RVs or even as fridge filters.
  • Good Value - True, the initial cost of these filters is higher than some other types, like faucet mount filters and pitcher filters. But, you save money in the long run because the filter elements don't have to be replaced as often. 

What are the disadvantages of under sink water filters?

  • Takes Up Cabinet Space - You save countertop space by using one of these filters, but the trade-off is less storage space under the sink. 
  • May Need Separate Faucet - Some models require installation of a separate faucet for the filtered water. That might mean having to cut a hole in the top of your sink.

Reverse osmosis vs filtration: What's the difference?

Like the models in this review, a reverse osmosis (RO) system goes under the kitchen sink, and it has a dedicated faucet.

But, unlike the others, an RO system has a semi-permeable reverse osmosis membrane that blocks up to 99% of most contaminants.

Here's a quick summary of other ways RO and under sink filters differ:



More expensive to buy & maintain

Generally more budget friendly

Uses holding tank, so takes up more space under sink

No holding tank

Wastes 1-4 gallons of water per gallon of filtered water

No waste water created

Removes healthy minerals

Leaves healthy minerals in water, thus no reduction of TDS

Excellent for fluoride removal

Generally doesn't remove fluoride, although a few models do

Blocks particles down to .001 micron

Blocks particles down to 0.5 to 1 micron

Removes viruses

Does not remove viruses

Because it's so different from the other under sink filters, there aren't any RO systems included in this review. Please see my review of the best reverse osmosis systems if you'd like more details.

What should I look for in an under sink water filter?

When you're shopping for an under sink water filter, you'll want to consider these details:

1. Contaminant Reduction

This is the most important feature of any water filter.

Almost any filter out there will remove chlorine and bad odors and taste. Maybe that's all you want.

But, chances are, you're concerned about other contaminants that can affect your health.

All filters are not the same, and they're not all equally effective. So take the time to investigate which contaminants are reduced and the per cent reduction that you can expect, based on independent laboratory testing.

Don't buy a filter that doesn't reduce at least 90% of the contaminants that you're most worried about.

Chlorine or Chloramine?

Municipal water suppliers have traditionally used chlorine to disinfect the water, but some are now using chloramine in addition to, or instead of, chlorine. Both substances affect the taste and smell of drinking water.

Most water filters remove chlorine, but many do not remove chloramine. So, you'll want to make special note of this when you're considering a particular model.

If you're not sure which one is used to treat your water, contact your water utility company. They are required by the EPA to provide annual Consumer Confidence Reports to their customers.

Suggested Reading: Chlorine vs Chloramine in Drinking Water: What’s the Difference and Why Does It Matter? (The Safe Healthy Home)

2. Filter Life Expectancy & Cost of Replacement

Most filter systems require filter element replacement every so often. That could be anywhere from every six months to three years, or even longer.

Most manufacturers will tell you the average filter life expectancy.

Several factors play into the longevity of the filter - the specific filtration media it uses, the volume of water you use, and the condition of your tap water, to name a few.

Estimate how often you'll need to change out the filter for the model(s) you're considering.

This will help you determine the ongoing cost of filtering your water so you can make an accurate overall price comparison.

3. Replacement Filter Availability

You don't want to spend money on a water filter and then find out that you can't find replacements anywhere.

Before you click the buy button, make sure that there are replacement filters available in a brick and mortar store or online.

4. Warranty

Just like any other product you buy, take note of any warranty or money back guarantee offered by the manufacturer. The longer the warranty period, the better!

5. Dimensions

One last item you'll want to check is the size of the system. Make sure you have enough room in the cabinet for the filter plus any existing plumbing. Pay special attention if you have a garbage disposal in there.

Mini Reviews: Best Under Sink Water Filters

1. Clearly Filtered 3-Stage Under-the-Sink Water Filter (best overall; removes fluoride)

Top of the list is the Clearly Filtered under sink water filter system.

It clearly outperforms the other brands in the types and amounts of contaminants it can reduce.

And it's the only one that removes fluoride.

Clearly Filtered under sink water filtration system

Shop for the 3-Stage Under-the-Sink Filter at Clearly Filtered

Clearly Filtered, a company based in California, is known for its high quality water filter pitcher, along with other types of water filtration products.


  • 3-Stage Filtration. Water makes contact with multiple layers of filtration media, yielding superior contaminant reduction results.
  • Leak Proof Filter Heads prevent spills and leakage when replacing filters.
  • Stainless Steel Water Lines last for years.
  • Cabinet Wall Mount saves space under the sink.
  • Dimensions: 16.75" high x 13.75" wide x 3.25" deep.
  • Parts Included: Three BPA free filter cartridges, two hoses, mounting bracket and screws.

Filter Effectiveness:

The Clearly Filtered 3-Stage outshines all the other under sink filters in terms of contaminant reduction. That's why it's at the top of the list.

One reason I'm such a big fan of Clearly Filtered is their transparency. They publish independent lab test results for their products on their website for the world to see. 

According to the data, this filtration system reduces more than 200 contaminants up to 99.9%. 

Here's a partial list of what it removes:

  • chlorine and chloramine
  • fluoride
  • lead
  • mercury
  • aluminum
  • arsenic
  • chromium VI
  • pesticides and herbicides
  • pharmaceuticals
  • radiologicals
  • PFOA
  • trihalomethanes
  • VOCs

What it doesn't remove:

  • viruses
  • microorganisms

Filter Life Expectancy:

One filter element set will last for 2,000 gallons. That's equivalent to about one year for the average household. Of course, large families will use it up faster, and if you're a single user, it'll last longer.

You should replace it when the flow of water slows down and/or the taste and smell start to degrade.

You can click here to check availability and price of a set of replacement filters at Amazon.

Or check the price at Clearly Filtered here. You can save 10% on the price by signing up for the Clearly Filtered filter replacement subscription program. They'll ship them to you for free as often as you like.


Clearly Filtered offers a lifetime warranty on the system. That's a rare find! 

Pros and Cons:

Clearly Filtered Pros and Cons

What People Like

  • Highly effective
  • Easy to install
  • Easy to replace filters
  • Made in the USA
  • Lifetime warranty

Don't Like So Much

  • Expensive
  • No bypass, so all water is filtered*

*If you only want to filter your drinking water, you can split the cold water line and install a dedicated faucet. Easy for a DIYer, or call a plumber.

Bottom Line: The Clearly Filtered 3-Stage is for those who want an under counter water filter system with maximum protection from contaminants. It costs more than the other models, but it is clearly superior in effectiveness.

You can also buy the system and replacement filters directly from Clearly Filtered. They offer free shipping, plus you can save by buying the pitcher bundled with replacement filters.

Click here to buy the 3-Stage at the Clearly Filtered website. Use the code WELCOME10 at checkout and receive an additional 10% off your purchase of a new filtration system.

2. CuZn UC-200 Under Counter Water Filter (longest lasting)

The CuZn (pronounced like the English word "cousin") UC-200 is one of the best selling and most popular under sink water filters out there.

That's probably because it has a super long filter life, it's reasonably priced, and it does a decent job of removing many of the worst contaminants. 

CuZn UC-200

Grab a long-lasting CuZn water filter at Amazon.


  • Three Stage Filtration: sediment membrane; KDF-55; and coconut shell granular activated carbon.
  • Bacteriostatic Filter inhibits the growth of mold and bacteria in the system.
  • No Extra Faucet Required. So, all cold water coming from your regular sink faucet is filtered.
  • No Maintenance Required. When the filter is used up, just throw the whole thing away.
  • Easy Installation. Simple to connect to your cold water line. Also, it stands on its base, so there's no need to attach it to the cabinet wall.
  • Dimensions: 4" diameter x 15.5" high.
  • All Parts Included. You'll get the complete filter assembly, brass fittings, and a 3 foot long braided stainless steel water hose. All you need to supply is an adjustable wrench to tighten the fittings.
  • Made in the USA.

Filter Effectiveness:

According to a data sheet I received from CuZn, the UC-200 can reduce the following contaminants:

  • chlorine (90%+)
  • lead (98%)
  • mercury (98%)
  • chromium VI (98%)
  • pesticides and herbicides (90%+)
  • pharmaceuticals (30-90%)
  • VOCs (90%+)
  • sediment

It does not reduce these contaminants:

  • chloramine
  • fluoride
  • nitrates
  • nitrites
  • microorganisms

This filter is intended to be used only with chlorine treated water from municipal water supplies. It would be okay to use with disinfected well water, too.

Filter Life Expectancy:  

The CuZn UC-200 filter lasts for an amazing 50,000 gallons or 5 years, whichever comes first.

This is great since there's not a separate faucet, and all of your cold water is going to be filtered. If you do the math, that works out to about 27 gallons of water per day. It's not likely you'll use even half that much.

The best way to tell when the filter is used up is by the taste and smell. You could also use chlorine test strips to test the water. When chlorine starts getting through the filter, you'll know it's time for a new one.


CuZn offers a 5 year warranty and 90 day "no questions asked" money back guarantee on the UC-200. So, there's really no risk in trying it out.

The company is also well known for its excellent customer service. If you have any questions or problems, they are quick to respond and resolve your issues.

Pros and Cons:

CuZn UC-200 Pros and Cons

What People Like

  • Takes out bad tastes and smells
  • Easy to install
  • Good flow rate
  • Inexpensive
  • Don't have to replace filters
  • Great customer service

Don't Like So Much

  • Doesn't mount to cabinet wall, so takes up floor space in cabinet
  • Doesn't remove fluoride

Bottom Line: If you're on chlorine treated city water and you don't care about reducing fluoride, the CuZn UC-200 might just be what you're looking for. Not having to install a separate faucet or trade out filter elements are big pluses. The long filter life and 5 year warranty also make it worthy of your consideration.

3. Woder 10K-Gen3-DC Under Sink Filter (cheapest)

Next up is the least expensive of the bunch - the 10K-Gen3-DC water filter by Woder.

It doesn't remove as wide a range of contaminants as the Clearly Filtered and CuZn do, but the low cost and long filter life make it a popular filter.

Woder 10K-Gen3-DC

Shop for the Woder 10K-Gen3-DC at Amazon.


  • Granular Activated Carbon (GAC) removes many common contaminants.
  • Bacteriostatic Filter keeps bacteria and mold growth at bay.
  • Uses Existing Sink Faucet. So, no need to cut a hole in your sink top.
  • Quick and Easy Installation. Takes 5 to 10 minutes on average to install. Attaches to cabinet wall.
  • Dimensions: 3" diameter x 16" high
  • All Parts Included: Filter assembly, two 18" lengths of tubing, fittings and screws.
  • Made in the USA.

Filter Effectiveness:

This filter does a moderately good job of reducing some common contaminants. It should only be used with chlorine treated water.

According to the Woder website, here's what this filter can reduce:

  • chlorine (99%)
  • lead (99%)
  • heavy metals
  • chromium VI
  • mercury
  • VOCs
  • turbidity
  • odors and tastes

It does not reduce:

  • fluoride
  • chloramine

Everything else about other contaminants and per cent reductions is unknown. The manufacturer has not published any independent lab test data. I have requested that information, and if they send it to me, I'll update it here.

Filter Life Expectancy:

This filter lasts a long time. It's good for 3 years or 10,000 gallons.

Keep in mind, though, that since it uses the existing sink faucet, you'll be using filtered water every time you turn on the cold water.

You get far less filtered water with the Woder than you do with the CuZn.

Click here to check the price and availability of the replacement filter at Amazon.


Woder filters come with a one year warranty.

Pros and Cons:

Woder 10K-Gen3-DC Pros and Cons

What People Like

  • Easy to install (as long as the fittings are the right size for your water supply)
  • Makes water taste and smell good
  • Inexpensive replacement filters

Don't Like So Much

  • Flow rate slows down a lot after a few months
  • No separate faucet wastes filtered water

Bottom Line: The Woder 10K-Gen3-DC is a good budget friendly choice for those whose main concerns are chlorine and lead in the water. 

4. iSpring CU-A4 Drinking Water Filter System (UltraFiltration for parasites & bacteria)

The CU-A4 water filter system is one of many offerings from iSpring, a family owned company out of Alpharetta, Georgia.

This is the only model in the top picks that uses an UltraFiltration membrane, giving it the ability to reduce a high percentage of parasites and bacteria.

iSpring CU-A4 water filter system

Shop for the iSpring CU-A4 at Amazon. 


  • Four Stage Filtration:  5 micron polypropylene sediment filter; UltraFiltration (UF) 0.1 micron hollow fiber membrane; KDF-55 and GAC hybrid filter; and fine GAC filter.
  • Optional Wall Mount. Filter assembly can stand on the cabinet floor or be screwed to the wall .
  • Lead Free Faucet Included. Dedicated faucet means filtered water is not wasted during dish washing, etc.
  • Color Coded Tubing makes installation easier.  
  • Easy Filter Replacement. Filter cartridges twist on and off .
  • Leak Proof Design. Water is routed in a way that prevents constant pressure on the filter. That means less chance of leaking.
  • Dimensions: 10.5" x 4.5" x 12.5"
  • All Parts Included. Comes with filter housing, 4 filter cartridges, water faucet, 15 feet of 1/4" tubing, 3/8" feed adapter, and Snap-Fit connectors.

Filter Effectiveness:

This system should be used only with potable water. It does an above average job of reducing contaminants, thanks to the combination of the four filters it uses.

ISpring had published lab test results on their website, so we can know how well the CU-A4 performs. Unfortunately, those results are no longer accessible online, but I did record some numbers.

Here's a partial list of the contaminants it can reduce:

  • sediment
  • chlorine (99%)
  • lead (98%)
  • copper, mercury, nickel (98%)
  • cysts (99.99%)
  • bacteria (99.99%)
  • VOCs (99%)
  • iron

And here's what we know it does not reduce:

  • chloramine
  • fluoride
  • chromium VI

Filter Life Expectancy:

Three of the filter cartridges - all but the UF - need to be replaced about every 6 months. The UF filter lasts about 12 months.

Fortunately, you can buy them in different combination packs, or separately, if you like. 

Check the current prices and availability of the CU-A4 replacements at Amazon here:


Individual filters (may be available with Amazon Subscribe and Save):


You'll get a 1 year limited warranty and free lifetime technical support when you buy this system. 

Pros and Cons:

iSpring CU-A4 Pros and Cons

What People Like

  • Great tasting water
  • Snap-fit connections work well and don't leak
  • Excellent customer service

Don't Like So Much

  • 3 of 4 filters only last 6 months
  • Expensive replacement filters
  • Poor installation instructions

Bottom Line:  The iSpring CU-A4 is a good choice if you don't need chloramine or fluoride filtration and you want some extra protection from bacteria and parasites. Just keep in mind that you'll have to change out the filters twice a year.

5. APEC WFS-1000 Under Sink Water Filter System (basic filtration)

Last of all, we've got the APEC WFS-1000.

APEC manufactures a line of top notch reverse osmosis filters, but that's overkill for a lot of people.

Sometimes you just want to get rid of the chlorine and make your water taste clean. That's what this system does, and very well, too.


Check out the APEC WFS-1000 at Amazon.


  • Three Stage System:  polypropylene sediment filter and 2 carbon block filters.
  • High Quality Lead Free Faucet. Attractive modern design with chrome finish.
  • Optional Wall Mount. If you'd rather not attach it to the cabinet wall, it can stand on its own on the floor. 
  • Easy Filter Replacement. Twist off the filter housing, switch out the filter, and twist back on.
  • Dimensions: 15" x 6" x 12"
  • All Parts Included. Comes with 3 filters, filter housings, faucet kit, feed water adapter, needle valve kit, 5 feet of 1/4" food grade tubing, housing wrench, and detailed instructions. 

Filter Effectiveness:

This system is designed to be used with city water or well water (with the caveat that the well has been tested and found safe).

Here's what it can remove:

  • chlorine
  • bad tastes and odors
  • VOCs (how much and which ones is unknown)

And here's what it can't remove:

  • chloramine
  • fluoride
  • lead or other heavy metals
  • biological contaminants

Filter Life Expectancy:

You'll need to replace the filters about once a year, or after 1,500 gallons - whichever comes first. When the water starts to taste funny, it's time to switch them out for new ones.

Click here to check the availability of the replacement filters at Amazon. 

(These are also used in APEC reverse osmosis systems. That's why the item title says "Set For ULTIMATE Series Reverse Osmosis Water Filter System Stage 1, 2&3".)


APEC offers a one year warranty on the WFS-1000 system along with lifetime support.

Their customer service reps are WQA certified, so they know their stuff and can help you with any problems you might have.

Pros and Cons:

APEC WFS-1000 Pros and Cons

What People Like

  • Easy to set up
  • Good quality faucet
  • Strong flow of water

Don't Like So Much

  • Doesn't remove lead

Bottom Line:  If all you care about is making your water taste and smell good, then the APEC WFS-1000 might be the filter for you. It seems like a lot of money to pay for limited effectiveness, though. 

Verdict: Clearly Filtered 3-Stage Under-the-Sink beats them all!

Phew! You made it to the end! That's a lot of information to digest.

So, the question is: Which one should I buy?

If you want the best protection from the greatest range of contaminants, the Clearly Filtered 3-Stage is my recommendation.

Second best is the iSpring CU-A4. It's almost as good as the Clearly Filtered, but it doesn't remove fluoride, chloramine or chromium VI. It also requires more filter changes.

If you want the cheapest overall, the CuZn UC-200 is the one to pick. It costs only a bit more than the Woder, but the filter lasts a good two years longer. It's not quite as good at removing chlorine and lead, though.

I hope you found this helpful in your search for a new water filter. Feel free to ask any questions you might have in the comments below. I'll do my best to get back to you quickly with an answer.

Last Updated on January 20, 2024

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  1. If comparing similar systems via price the APEC RO systems are absolutely top notch and are rated to remove upwards of 97% of lead from drinking water. My well water was lab tested the year before last and after filtering with the APEC there were no detectable levels of any contaminates including heavy metals or pesticides even though I live next to a large farm. After 5 years of ownership, and considering price versus performance, it is tough to beat an APEC system. And it is made in the USA.

  2. Thinking of pulling the trigger on the Propur under counter system – we currently have their gravity system and love it. Before doing so, any thoughts on the Hydroviv or Pristine Hydro systems?

    1. Hi, Lani! No, sorry – I’m not familiar enough with them to give an opinion at this time. I will definitely check them out, though.

  3. Hi Marge,
    I have been researching under counter water filters and was surprised to see that none of your picks and Consumer Report picks were the same. I am curious why and am wondering if you could shed light on that. I spoke with our Water District Manager in length today and he gave me the rundown of the water in our town which is very good. He only uses a Brita Filter himself, which is what I currently have, and said that would be enough to filter lead and VOC’s. Our water is not floridated and is purified by chlorine and goes through greensand filters.
    Thank you for any comment that will help me decide. I would like to get an under the sink filter but I don’t need a RO filter. Thank you very much, Sandy

    1. Hi, Sandy! That’s a great question, and one I never really thought about before.

      I did a little research, and learned that CR does lab testing on products for initial ratings, but their method of rating reliability is based on prediction, not actual facts. They say this in an article about reliability of appliances: “To calculate predicted reliability, we asked members how many times the products they own broke or stopped working as well as they should. We used that data to estimate how new models from a given brand will hold up over the first five years.”

      There certainly is some validity to this method, but I think more people than not want to know what real users have experienced. That’s why online reviews are so popular and so important. I recently bought some new appliances for my kitchen, and I read every consumer review (on the models I was considering) at Home and before making a decision.

      My research for reviews on this website involves studying technical data and reading lots and lots of online consumer reviews. I want to know the ins and out of how something works, and I also want to know how it works in real life with real people over a period of time.

      So, there’s that aspect. But I don’t know how CR chooses which products it will review. Does it review every single water filter out there, for instance? Or does it only go with the big name brands? I have no clue.

      Anyway, I really don’t have an answer for you. I can only guess, and my guesses are probably wrong! Haha! If you or anyone else reading has any insight, I’d be interested to know.

      As far as your choice of water filter goes, it sounds like your water quality is pretty good. You didn’t say so, but I’m thinking you’re mainly concerned with removing the chlorine and improving the taste and smell. If that’s so, you’d probably be happy with a basic activated carbon filter.

      I hope this helps.

  4. Hello I am in the market for a under sink filter and was suggested CWR metalgon and ceramic filter combination, so expensive! Then I discovered Aquacera has a similar combination for less than half the price. Now reading your reviews I discovered Propur and sounds really good. Any insight on CWR and Aquacera? How do you think they compare to Propur? Thank you for your great research, it really helps!

    1. Hi, Carlo! I’m not familiar with CWR. Can you give me a link to the specific model you’re talking about? And which Aquacera model? I’ll be glad to do some research if you can be more specific. Thanks.

  5. it would be useful if you had a table comparing what % of each contaminants these filters remove, similar to what you have on the page for gravity filters. thanks for a great website.

  6. Thank you for the recommendation. I am considering cuzn200 as it looks simple and last longer. If i have one handle faucet, and if i run medium temp water, should i get two?

    1. Hi, HK! You can buy a separate filter for the hot water line, but it might not last very long. Granular activated carbon works best with cold water. Hot water can make it clog up, so you’ll quickly lose effectiveness. This type of filter is really just made to use with cold water.

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