Best Under Sink Water Filters – Reviews and Buying Guide

The water we get from our kitchen sink is primarily used for drinking and cooking. People want to ensure that they are getting the purest and best quality possible water from in their kitchen. If you don’t filter your water, not only will your water probably not taste and smell as good, you may be leaving yourself susceptible to illness.

Most of us take our water supply for granted. You may not think about it on a daily basis, but depending on where you are in the world, your water supply may have contaminants in it.

As they are kept in such close proximity to your faucet, the best under sink water filters have the advantage of not having to travel through as many pipes in your home, and this can minimize the risk of other elements entering the water through your home’s plumbing.

None of the under sink water filters in this list are RO (reverse osmosis) systems. If you are looking for this category of filter, we have a separate article which discusses the best RO systems for installation in the home.

30 Second Review

If you’re in a hurry, here are some of the key considerations for choosing the right under sink filter for your needs.

Evaluate what the main issues with your water are, whether it is likely to have lead in it, or the chlorine level is high. Match your filter choice up with which contaminants it is strongest at removing. This will be based on the filter type (more on that below).

If you have multiple contaminants or want to be especially thorough with your filtration, consider multi-stage filters. This is like having multiple filters built into the same model.

If your home uses a lot of water and you don’t want to be constantly replacing the filter, get something with a high capacity. This way you won’t have to replace it as regularly.

Most under sink filters can be installed yourself, without a professional plumber. Check the size of the filter and also check our reviews for ease-of-install. The process should take less than 30 minutes.

Do I Need an Under Sink Water Filter System?

Even if you already have a whole house filter system, combining it with an under sink model is often safest. The whole house system will treat water at the point of entry, and are often designed for water supplies containing a lot of minerals. If you have issues with your pipes, their coating, or erosion, the water can become contaminated within the home even after the initial treatment.

Unfortunately, crises such as the Flint water crisis in which lead from water pipes got into the drinking water of over 100,000 people, have shown the risk pipes can pose if in poor condition or eroding. Lead was commonly used in pipes historically, and if you have a home built in the 1980s there is a chance of lead poisoning. It wasn’t until 1991 that lead and copper were outlawed in plumbing via the EPA’s Lead and Copper Rule.

Even elements traditionally not seen as contaminants are often best filtered out. The elements used to treat municipal water supplies can have some harmful effects. For instance, chlorine is used to kill bacteria, but studies show that in the long term, it can be linked to increased chances of bladder and rectal cancer or developmental issues among infants.

Most of the under sink filters we’ve reviewed in our list focus on chlorine, or chemical compounds containing chlorine, such as chloramine, as well as removing lead. Some filters’ main focus is chlorine, as lead may not be a big issue in certain areas. Filtering Fluoride, sediment, heavy metals and other contaminants are also effective in many of these filters.

Media Types - Carbon and Multi-Stage Carbon

A single-stage water filter will have only one filter cartridge, usually a carbon block. This is not the most effective strategy. Multi-stage filters have various different types of filters or ‘filter media’, all of which have different pore sizes (this is measured in Microns). By forcing the water through multiple filters, you increase the chances of removing different elements. While one stage of filter media might reduce heavy metals more effectively, the next may remove chlorine, and so on.

Activated carbon is a very popular filter media. It has the ability to effectively remove organic compounds as well as chlorine. This can vastly improve the taste and quality of water but doesn’t tackle lead as well as RO, no does it deal with bacteria as well.

For this reason, many of the top under sink water filters are designed to combine both a carbon block with an RO membrane. This way, you get the best of both worlds and are protected from most contaminants.

Multi-stage filters often include activated carbon, UF (ultra fine filtration for removing even the smallest elements under 0.1 microns), KDF filtration (which uses zinc and copper to attract both negatively and positively charged elements) and other carbon blocks. Each manufacturer has their own combination.

Multi-stage filtration is recommended for everyone, but especially for homes with young people, pregnant women or those suffering with diseases. The protection a multi-stage water filter provides from both microorganisms, chlorine and other harmful substances which can impact infants extremely negatively.

Should I Trust a Filter?

How do you know that you can trust a water filter? Does it do the job it says it does? NSF certification is a good way of knowing what a filter is capable of. Different NSF ratings (NSF 53, for example) are awarded to products based on what they are capable of, and which contaminants they remove.

Be warned that in order to get this certification, the filter often only has to be effective for one contaminant from a list of fifteen. A filter which removes only one or two of the NSF’s list of recognized contaminants can have the same rating as one which removes 10 of these. For this reason, reading reviews is the best way to get a full picture of whether a filter is effective.

Best Under Sink Water Filter Reviews

Image                 Product

CuZn UC-200 Water Filter

CuZn UC-200

  • Capacity: 50,000 gallons
  • Lifetime: 5 Years
  • Reduce Sediment, Chlorine Taste & Odor,  heavy metals (lead, mercury, chromium VI, cadmium, etc.), herbicides, pesticides,, algae, molds.

Best Overall

Filtrete Advanced 3US-PS01

Filtrete Advanced 3US-PS01

  • Filter Life: 6-month
  • Flow Rate: 2.25 GPM
  • Reduces Sediment, Chlorine Taste & Odor, Microbial Cysts.

Best Value

Culligan EZ-Change Basic US-EZ-1

Culligan EZ-Change Basic US-EZ-1

  • Filter Life: 12 Months, 3,000 Gal.
  • Flow Rate: 0.5 GPM
  • Reduces particulates class III, chloride and removes bad taste and odor.

Best Budget

Woder 10K-DC

Woder 10K-DC

  • Filter Life: 3 Years, 10,000 Gal.
  • Flow Rate: 3 GPM
  • Eliminate Lead (99.9%), Heavy metals, Chlorine (99.9%), Chromium 6, Volatile Organic Compounds and other contaminants (99.9%), odors and bad tastes, Mercury and turbidity.

​Best for Lead

Woder 10K-FRM-DC

Woder 10K-FRM-DC

  • Filter Life: 2 Years, 5,000 Gal.
  • Flow Rate: 1.32 GPM
  • Removes up to 95% of Fluoride, Eliminates lead (99.9%), heavy metals, chlorine (99.9%), chromium 6, mercury, volatile organic compounds, carcinogens, and other contaminants, as well as turbidity, odors and bad tastes.

​Best for Fluoride

iSpring CU-A4

iSpring CU-A4

  • The 0.1 micron Ultra Filtration (UF) stage removes up to 99% of most problematic pollutants such as chlorine and chlorine treatment by-products, bacteria, giardia, lead, arsenic, and much more, while retaining healthy minerals.

​Best for Bacteria

Ecosoft 3 Stage FMV3ECOUS

Ecosoft 3 Stage FMV3ECOUS

  • Flow Rate:0.25GPM
  • removing bad smells, taste, chlorines & chloramines, lead, water softening, copper aluminum, barium, iron, salinity, manganese, and other heavy metals.

1. CuZn UC-200 Water Filter - Best Overall

CuZn UC-200 Water Filter

Filter Life

50,000 gallons or 5 Years

Stages

3

4.9 out of 5 stars

This is our top-rated overall under sink water filter. It has a huge amount of features and extremely thorough filtration which leaves exceptionally pure water by removing lead, mercury, chromium V, herbicides, pesticides, and many more contaminants.

The CuZn is not advertised as a reverse osmosis filter, but it does feature a Micro Sediment Membrane which has a similar effect. Micro Sediment means 0.1 micron pores, which is suitable for removing even the most minescule contaminants. This filter is combined with two other stages, a KDF-55 and Coconut Shell filter which provides activated carbon.

Some carbon filters are susceptible to growing mold, but due to the fact that the UC-200 has been designed to be bacteriostatic, this is not an issue with this mode.

The manufacture of this product takes place in the USA, and the quality is unquestionable. The capacity means that it can last for the filtration of 50,000 gallons which works out at around five years of usage. The 90 day manufacturer guarantee means that in the unlikely event that you are not satisfied you can get a refund. CuZn’s customer support team have a dedicated phone line to helping with issues around plumbing or other problems.

Installation is simple. It connects to your cold water line. The only tool you require for installation is an adjustable wrench. CuZn have even prepared a specific installation video to help with the process. It comes with ⅜” inlet and outlet fittings.


2. Filtrete Advanced 3US-PS01

Filtrete Advanced 3US-PS01

Filter Life

6-month

Flow Rate

2.25 GPM

4.3 out of 5 stars

Filtrete is manufactured by 3M, who are global manufacturers of scientific products and equipment. 3M’s testing is rigorous and the 3US-PS01 has been shown to reduce the taste and odor of chlorine as well as getting rid of microbial cysts, sand and silt as well as rust and sediment.

Vitally, the Lead reduction is quite efficient and in most homes this will be more than enough to ensure that your water is free of any significant levels of lead.

The target safe amount of lead for water is zero, as outlined by the EPA. If you are concerned, you may want to combine the Filtrete with another filter or go for a system with more thorough led removal such as the Woder 10K-DC (below).

At a relatively affordable price tag, this is a good value for money under sink filter. It doesn’t compromise on your water flow rate and also takes just 30 minutes to install. It installs to your existing kitchen faucet so you don’t need a dedicated one.

This is an efficient and simple system with NSF certifications 42 and 53. Unless you have specific lead problems and need something more heavy-duty to deal with this, it may be a good option for your home. If you do opt for this model, you will have to replace the filter cartridge every six months or even more frequently if you are in an area with a lot of contaminants.


3. Culligan EZ-Change Basic US-EZ-1 - Best Budget Under Sink Water Filter

Culligan EZ-Change Basic US-EZ-1

Filter Life

12 Months, 3,000 Gal.

Flow Rate

0.5 GPM

4.1 out of 5 stars

The Culligan EZ-Change is available at a very reasonable price, and is a budget water filter which we are happy to recommend. It doesn’t quite have the same high-level features as the elite models, but it is very good for removing the chlorine taste and odor from water. If your main problem with water is the quality in terms of enjoyability then the US-EZ-1 could be an affordable way to treat water.

Though this model of filter reduces particulates class III, it is not effective at filtering out microbial bacteria and doesn’t provide the highest level of safety for your water. If you can be confident the water is already at a high standard coming into your kitchen and you just want to improve its taste then this is an adequate choice. It comes with a dedicated faucet, but this will fit the vast majority of kitchen sinks.

It is easy to install, and the filter lasts for 3,000 gallons which should provide around a year of use before replacing the water cartridge. It only has 0.5 gallons per minute of flow rate.


4. Woder 10K-DC - Best Under Sink Water Filter for Lead

Woder 10K-DC

Filter Life

3 Years, 10,000 Gal.

Flow Rate

3 GPM

4.4 out of 5 stars

The Woder is a very high-quality filter both for safety and for the taste and smell of your water. It is designed to be used in conjunction with municipally treated water rather than well water. This is the best filter on our list for removing lead.

The independent tests show this meets ANSI (American National Standards Institute) standards, and remove 99.9% of all lead. If lead is your main issue then it is difficult to find a more effective model that fits under the sink. Lead isn’t the only contaminant the Woder deals with. It also has 99.9% efficiency at removing chlorine (another huge problem in many homes) and many volatile organic compounds. Mercury and chromium 6 are also removed.

A side effect of all this removal also means a vastly improved taste and odor.

Not only is this an exceptionally highly-rated filter, but it also lasts a long time before needing replacements too. The 10K in the title is due to the fact it lasts 10,000 gallons before having to install a replacement filter cartridge. 3 GPM flow rate means it can handle plenty of water running through.

Easy to install, it works using ‘direct connect’ which doesn’t need any actual plumbing and can easily plug directly into your existing cold water supply and then the faucet stem.

The manufacturers describe the water provided as “as pure and healthy as spring water”. For thorough chlorine and lead removal, the Woder is impressive, and only beaten by some multi-stage filters.


5. Woder 10K-FRM-DC - Best Under Sink Water Filter for Fluoride

Woder 10K-FRM-DC

Filter Life

2 Years, 5,000 Gal.

Flow Rate

1.32 GPM

4.4 out of 5 stars

Having already spoken so highly of the Woder 10K-DC model, you may be surprised to learn there is a model which is more of an upgrade. This is a two-stage filtration system designed to handle Fluoride in water as well as lead, chlorine and other contaminants.

The 10K-FRM-DC connects in the same simple way as its sibling product, which is very simple.

The key differences are the fact that it has the FRM Fluoride Filter to remove Fluoride from the water supply. This further helps with other elements too meaning 99.99% of all contaminants are removed by this filter.

The sacrifice is that the flow rate drops to under 1.5 GPM and the filter will need replacing every 5000 gallons.


6. iSpring CU-A4 - Best Under Sink Water Filter For Bacteria

iSpring CU-A4

Filter Life


Flow Rate


4.3 out of 5 stars

The iSpring is designed with bacteria removal in mind. A 4-stage filter has Activated Carbon, Ultrafiltration (0.1 micron) and KDF/GAC filtration, which features a zinc and copper filter which uses electrochemical oxidation-reduction which adequately removes chlorine, chlorinated hydrocarbons, and many different metals.

These four stages are able to filter virtually every size of pollutant and contaminant, making it so effective against bacteria of all different sizes.

The iSpring CU-A4 is very small, so it can easily be installed under the sink. It installs inline, so it could even be used in an RV or as a fridge filter if you needed. The maintenance couldn’t be easier, as the cartridges twist on and off when the time comes to replace them.

The CU-A4 has been tested to NSF standards as well as ANSI and FDA. It is well-built and has a one year warranty.


7. Ecosoft 3 Stage FMV3ECOUS - Best Under Sink Filter for Chloramines

Ecosoft 3 Stage FMV3ECOUS

Filter Life


Flow Rate

0.25 GPM

4.5 out of 5 stars

Chlorine by-products are often referred to as BPD, The Ecomix 531 filter, one of the three materials in this 3-stage filter, specializes not only in removing chlorine, but chloramines and other by-products. This filter also does a good job on lead, though not quite as thorough as some of the other filters on our list.

The other two stages of the filtration are 5-micron PP Sediment and Coconut Shell activated carbon. The sediment removes anything larger than five microns such as silt and sand, and the coconut shell makes your water fresh and odorless.

One disadvantage is the fact that installing the ecosoft will mean you only have 0.25 GPM flow rate, which is lower than any other product on this list. The installation is relatively simple, and the dedicated faucet for this filtered water is included with the product when purchased.

Buying Guide and Considerations

Learn About Your Water First

Before choosing exactly which water filter to buy, it makes sense to know what you are dealing with. You can learn more about your water by conducting simple tests or from readily-available information. The EPA have guidelines on how to test for lead in your water. Your local consumer confidence report will tell you a lot about the water in your area, but this does not account for the pipes within your home.

WHO have provided guidelines on testing for chlorine within your water.

By learning a lot more about your water supply (and the plumbing of your home) you can establish the highest risks and plan which under sink filter is most appropriate for your home.

Flow Rate

As the water works its way through the filter, the flow rate can be reduced. As long as your faucet is not designed to dispense water faster than this flow rate, you shouldn’t notice any difference. If the faucet has a low flow rate then you might end up experiencing issues with the water being dispensed slowly.

Flow rate is effectively how quickly the filter can push water through to the other side whilst staying effective.

Installation

Most of the top under sink filters will install ‘inline’. This means they will use the water from your cold water supply line (this is the input of the filter) and then dispense to the faucet. All of the products on this list have adequate instructions on installation, and there is no reason you should need to get a professional plumber to install your filter. It is a simple process in the majority of situations, and should take no more than 30 minutes.

Ensuring that your filter is compact enough to fit under your sink is key. If you don’t have a lot of space there then the process can be more of a challenge.

Maintenance and Filter Cartridge Capacity/Replacement

The maintenance of a filter will usually just mean replacing the filter cartridge after a period of time. The filter will deteriorate slightly over time, and needs to be replaced once it has treated a certain amount of gallons of water.

Most kitchen Faucets use between 6,600 and 9,750 gallons of water per year. Use this as a guideline for how regularly to replace your filter.

Conclusion

The key consideration when choosing the best under sink water filter for you should be which contaminants you need to filter out most urgently, and matching up the most suitable filter for your needs. All of the filters on our list have their own strengths, which we have pointed out to make the decision easier for you, whether your main concern is bacteria, lead, chlorine, or all of these.

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