Best Under Sink Water Filter Systems

In the following article, we look at the best under sink water filter systems available on the market today and provide detailed reviews on what makes them stand out compared to the rest.

11 Best Under Sink Water Filters in this review:

Under Sink FiltersSpecs
CuZn UC-2003-stage filtration
Woder WD-S-8K-DC3-stage, 1 filter cartrdige
APEC WFS-10003-stage filtration
APEC CS-25005-stage, 2 filter cartridges
iSpring US313-stage filtration
Aquasana AQ-52001-stage filtration
Aquasana AQ-5300+2-stage filtration
Culligan US-EZ-42-stage filtration
Filtrete Maximum (3US-MAX-S01)1-stage filtration
GE GX1S50R Under Sink Water Filter1-stage filtration
Whirlpool WHAMBS53-stage filtration

Below is our list and in-depth reviews of the best under sink water filter systems that we believe really stand out in terms of performance, efficiency, capacity, reliability, and overall quality. If you are thinking of getting an under sink water filter, then these are the best models you should consider.

You will find sufficient information about these must-have devices regarding what they are, how exactly they work, their main purpose, and their benefits.

CuZn UC-200

Key Features:
  • High capacity of 50,000 gallons and flow rate of 2 GPM
  • 100% efficient with zero wastewater generation
  • Removes a wide range of organic and inorganic contaminants

The CuZn UC-200 is one of the best top-rated under sink water filters on the market. What makes it highly popular is its impressive filtration features, advanced design, quality, super efficiency, and convenience all at a relatively fair price. More importantly, it has the most long-lasting filter offering the highest capacity on our list.

Filtration Performance

The CuZn UC-200 model utilizes a 3-stage filtration process which consists of a micro sediment membrane, KDF-55 filtration media, and virgin acid washed catalytic carbon filtration media made from coconut shell carbon.

This impressive filtration process and advanced materials remove a wide range of contaminants from your water both inorganic and organic.

The first media which is the micro sediment membrane helps clear out sediments and tiny particles from the water.

The KDF-55 media and catalytic coconut shell carbon combination, on the other hand, work effectively to remove many different kinds of harmful chemical contaminants found in the water and the pipes.

The first main items they eliminate are chlorine, chloramines, and chlorine byproducts like chloromethanes and bromoform. The robust catalytic coconut shell carbon filtration media is also capable of reducing most types of pharmaceutical and perfluorinated (PFOA) compounds.

It can reduce Glyphosate too and several volatile organic compounds found in municipal water.  In short, it will basically remove almost all chemical contaminants that often affect the taste, odor, and quality of water.

The UC-200 KDF-55 filtration media stage, in particular, does a great job of reducing up to 98% of all the water-soluble cation heavy metals like lead, chromium, nickel, mercury, cadmium, and other dissolved metals.

Another commendable thing about this unit’s filtration process is that it purifies the water selectively. It will not remove the beneficial hardness minerals such as calcium and magnesium. Therefore, you get clean filtered water with the healthy minerals present.

Bacteriostatic Filtration System

One of the best features of the CuZn UC-200 model is its bacterial growth prevention. It is bacteriostatic which means bacteria can’t grow within the unit as is the case with carbon-only filters which are susceptible to building up of microorganisms over time when not changed frequently.

The inclusion of the KDF-55 media helps create a bacteriostatic environment in the unit which limits any possibility of microorganism growth and also kills any bacteria present in the water.

By direct electrochemical contact and flash formation of hydrogen peroxide and hydroxyl radicals, this KDF redox media causes cellular damage to the microorganism lingering inside the unit by disrupting their ability to function thereby destroying them completely.

As such, there’s almost zero chance of bacteria, mold, and algae building up within the system thereby preventing any further contamination of the water and the potential spread of water-borne diseases.

Capacity and Efficiency

The CuZn UC-200 offers an incredibly high capacity as it is able to filter a maximum of 50,000 gallons of water on demand throughout its lifespan. Basically, you will be using it for nearly 5 years or even longer if it’s only for drinking water and cooking.

The unit is also built to withstand a great deal of pressure. It’s capable of handling up to 130 psi operating pressure which is a big bonus considering that the city water pressure in most homes is around 60 psi.

The flow rate is equally high as the system can produce about 2 gallons of filtered water per minute and the best part is no wastewater is generated in the process, so it’s 100% water efficient.

Installation and Maintenance

Installing this CuZn system is super easy. All the necessary parts required to hook it up under your home or office sink are provided.

The unit is designed to filter cold water from the municipal/city water treatment supplies alone. It’s not recommended for use with private well water suppliers. 

A separate dedicated faucet for the filtered water is not required since it can work with an existing cold water faucet. However, if you prefer to install it, the manufacturer provides a complementary alternative installation kit for the dedicated filtered water faucet setup upon request at no additional cost.

Almost no maintenance is needed because the filter it uses is long-lasting. You will only have to change the system after around 5 years and the process is simple as the first time you install it.

One downside we noted with this unit is that it does not consistently reduce a high percentage of fluoride. It reduces the levels by just 20 to 30% on average.

It’s also not the right choice for dealing with excessively hard water issues brought about by extremely high mineral content since most of these minerals are allowed to pass through the filter.

Overall, this CuZn UC-200 model is a top under sink water filter that offers reliable general purification of municipal water issues. If you want a more basic yet effective low maintenance and long-lasting water filtration system, then this is an option worth investing in.


  • Removes a wide range of organic and inorganic contaminants
  • Kills and restricts the growth of bacteria and mold within the system
  • Incredibly high capacity (50,000 gallons) and flow rate (2 GPM)
  • 100% efficient with zero wastewater generation
  • Setting it up is a breeze and almost no maintenance needed
  • Long-lasting filter offering up to 5 years of service
  • Comes with a 5-year limited warranty


  • The “in” and “out” flow not indicated on the unit
  • Filters only municipal water

Woder WD-S-8K-DC

Key Features:
  • Effective filtration process that’ll remove 99% of contaminants
  • Eliminates bad odor better and prevents microorganisms build-up
  • Uses selective filtration technology which keeps essential minerals

The Woder WD-S-8K-DC, just like the CuZn-200 above is really popular under sink water filters and this is mainly due to its simplicity and effective filtration ability.

The other thing that makes it very attractive to many is the large capacity it has, in fact, it’s the second-highest on this list. If you are looking for a compact unit that can give you good value for your money, then this may be the best choice for you.

Filtration Performance

Although quite small, this powerful water filter is extremely capable of reducing a huge percentage of contaminants that water treatment facilities fail to remove as well as those picked up along the way.

The filtration media the system uses is a special blend of granulated carbon and silver that have been grounded to microparticles, screened, and then blended together rather than layered.

This filter design provides a large surface area hence ensuring optimum contact time with the water which extremely boosts the absorption ability of the filter making it super effective at extracting contaminants from the water.

It will be able to remove 99.99% of chlorine and lead plus many more other contaminants like VOCs, carcinogens, chloramine, as well as heavy metals such as mercury and chromium 6.

It will filter out turbidity too and get rid of that unpleasant odor and tastes often caused by most of the chemical contaminants in the water. In addition to that, the Woder 8K is bacteriostatic, so it will prevent the growth of bacteria, mold, or any other microorganisms within the filter.

Its special blend of media also gives it a selective filtration ability which clears out harmful impurities but keeps all the essential minerals that are vital to our health, including calcium, magnesium, and potassium. Therefore, you and the family will get to enjoy healthy and great-tasting purified water.

Capacity and Efficiency

This Woder WD-S-8K-DC is an under sink water filter with a large capacity as it can process up to 8, 480 gallons of water before needing a change of filter which is the second-highest capacity on this list.

It means it can last more than 3 years with normal use hence it’s ideal for long-term use. If you are not a fun of changing filters frequently, this will fit you right. 

Regarding the flow rate, the filter will deliver around 2 gallons of water a minute at 65 psi which is the average rate of most under sink filters. The best part is the fact that it uses microparticles means that it will be able to remain optimally effective while purifying your water for those 3 years.

However, this will only be possible if you make sure you use it with municipally treated cold water alone or at least disinfected water, not well water.

Installation and Maintenance

With its simple and compact design, the installation process of the Woder 8K is easy and straightforward. It shouldn’t take more than 5 minutes. The package features all the parts you need including the direct connect hoses.

You just mount it where you want and connect it directly to your 3/8” cold water line under the sink and the existing standard cold water valve faucet. You don’t need a separate dedicated faucet to dispense the filtered water.

Low maintenance is another advantage you will get from this filter since it can for about 3 years before requiring changing and it has a built-in valve to allow you to perform the replacement without turning off the water. You will have to replace the whole thing though.

To sum it all, Woder WD-S-8K-DC is a very capable under-sink water filter that will give you amazing value for your money, especially because of its high capacity. It’s a suitable choice for city water and its construction feels solid and strong, so you are assured durability.


  • Effective filtration process that’ll remove 99% of contaminants
  • Eliminates bad odor better and prevents microorganisms build-up
  • Uses selective filtration technology which keeps essential minerals
  • Relatively high capacity that can serve you for more than 3 years
  • Easy to install and requires low maintenance
  • Comes with a 1-year limited warranty


  • Does not remove fluoride
  • May reduce water pressure a bit


Key Features:
  • Designed for removal of sediments and chemical contaminants
  • Eliminates unpleasant tastes, odors and water cloudiness
  • Doesn’t interfere with essential minerals or water alkalinity

APEC is a reputable manufacturer of water filtration systems with a long history of producing quality products. Their WFS-1000 under sink water filter system does not disappoint either as it’s amongst their top products with much positive reception. 

It’s a basic under sink water filter designed purposely for removing chemical contaminants from the water, especially chlorine. If your water is already good but you just want to refine it and protect yourself against any potential contamination, then this is a nice option to check out.

Filtration Performance

The WFS-1000 has 3 filtration stages consisting of a sediment filter and two carbon block filters which together provide a commendable filtration performance.

At the 1st stage is the high-grade 10″ polypropylene sediment filter which extracts as many sediments as possible from the water including dust, rust, silt, and other tiny and major particles in order to protect and maintain the filtering ability of the next stages.

The water then goes through an extruded carbon block filter in the 2nd stage which is typically made up of activated carbon particles fused together into a single block.

This serves as the first point of carbon filtration where a majority of the chlorine, VOCs, and other chemical contaminants like pharmaceuticals, pesticides, and herbicides are initially removed from the water. Unwanted tastes, odors, cloudiness, and residual sediments are cleared out as well at this stage.

The 3rd stage has the same extruded carbon filter which performs the final refining by further removing the remaining chlorine, odor, tastes, color, cloudiness, and other chemicals.

The use of these dual carbon filters significantly boosts the filtration performance of the unit allowing it to get rid of almost all the chlorine, tastes, and VOCs from the water, and also organic chemicals.

The mineral composition and alkalinity of the water do not change throughout the filtration process. The result is mineral-rich water that’s clean, looks clear, and tastes fresh.

Capacity and Efficiency

APEC has not specified the total gallon rating for this WFS-1000 model but if we have to give an estimate, it will process more than 1,000 gallons of water before needing replacement.  

For a lot of households with regular normal usage, this means it’s likely to last 1 to 2 years provided your water is not highly contaminated. It’s a decent lifespan compared to most similar systems.

Although the unit uses three filtration stages, you won’t notice a big change in the water flow. It has a maximum flow rate of 1.6 gallons per minute, thereby it will filter the water quickly and provide a continuous on-demand supply of clean purified water to your faucet. Furthermore, no water is wasted, so your monthly water cost won’t change much.

Installation and Maintenance

The WFS-1000 comes fully assembled for installation. What’s required is to mount it in the desired location, insert the filter cartridges, and connect the tubing.

The challenging part may be to install the faucet as it’s designed to work with a separate dedicated faucet for dispensing the filtered water.

The package comes with a 100% lead-free chrome faucet, hence if there’s no pre-made hole in your kitchen counter, you might have to drill one to install this faucet.

The unit falls in the medium to large size end and as such, it should fit under most standard kitchen cabinets. If it’s small, then you will have to adjust some stuff to create room for it.  

There’s little work to do with regard to maintenance because it’s just replacing the filters at least after every 12 months and it’s equally an easy and quick process.

Now one of the setbacks of this unit is that despite having dual activated carbon filters, it still cannot eliminate chloramine from water which might be a concern for those living in cities that utilize chloramine to treat water instead of chlorine.

According to APEC, the filter will also not remove fluoride, bacteria, and heavy metals like lead and arsenic. Total dissolved solids as well pass right through the filters. What this generally means is that it’s not ideal at all for filtering well water.

In conclusion, as long as you are seeking to purify only municipal water that’s treated with chlorine, the APEC WFS-1000 will be a better fit for you. It will serve you for a long and deliver the water quality you desire.


  • Designed for removal of sediments and chemical contaminants
  • Eliminates unpleasant tastes, odors and water cloudiness
  • Doesn’t interfere with essential minerals or water alkalinity
  • Can process more than 1,000 gallons of water before replacement
  • Installation is fairly easy as well as changing the filters
  • Comes with a 1-year limited warranty and a dedicated standard faucet


  • It’s not able to filter out chloramine, fluoride and heavy metals
  • Not the most compact under sink water filter system

APEC CS-2500

Key Features:
  • Removes a good number of contaminants
  • Destroys and prevents bacterial build-up
  • Essential minerals remain in the filtered water

Our next under sink water filter is the APEC CS-2500 water filtration system. This is a strong but more basic under sink water filter from APEC built to provide dependable filtration at an affordable price. It’s a good starting point for those who are looking for a simple, budget under sink filter for improving the quality of their city water.

Filtration Performance

The APEC CS-2500 filtration process relies purely on a single filter cartridge for the removal of several different kinds of contaminants commonly found in water supplied from municipal treatment plants.

It utilizes a carbon block filter which may seem like a standard carbon filter but it does offer a respectable contaminant rejection rate. This highly porous medium is able to eliminate up to 97% of chlorine, bad tastes, odors, and various other chemicals such as herbicides and pesticides from the water.

The media is also capable of removing 90% of all lead plus other heavy metals while ensuring that essential minerals like calcium and potassium remain in the water. It’s a much ideal filter for dealing with lead or anything chemical that contaminates your water.

Besides that, it’s designed to be bacteriostatic and as such, it will as well remove heterotrophic bacteria and inhibit them from growing or reproducing within the unit which is a big plus in preventing any possibility of further contamination happening inside the filter.

Capacity and Efficiency

Like the APEC WFS-1000, the exact filtration capacity of this APEC CS-2500 model has not been clearly specified but according to APEC, its maximum contaminant reduction capacity is around 5,000 gallons and that should allow the filter to go for up to 12 months before you can change it.

The water flow rate is 1.67 gallons per minute which is good enough to ensure you get filtered water on-demand quickly plus you won’t notice any drop in water pressure when using the filter.

Installation and Maintenance

The best part of this unit aside from its filtration ability is that it offers a trouble-free installation. Using the provided standard 3/8” connector, you screw in the inlet line from the filter directly to your cold water supply valve and then screw in the outlet line to your existing faucet stem.

It’s that easy and you don’t require a separate faucet. The lines will handle pressures of up to 125 psi thanks to the twist connection design and they are likely to leak under high pressure compared to push-in hoses.

This quick twist connection design also enables easy filter replacement which you won’t have to do more frequently as the filter cartridge lasts up to 12 months without changing out. The lifespan may vary though depending on the quality of water going into the unit.

Generally, there’s little to worry about this under-sink water filter. It’s a basic and economical water filtration system suitable for removing chlorine, heavy metals, and a few other contaminants from treated municipal water. Due to its compact size as well as easy installation, it can be a perfect choice for RV owners.


  • Removes a good number of contaminants
  • Destroys and prevents bacterial build-up
  • Essential minerals remain in the filtered water
  •  Decent flow rate and filter lifespan
  • Easy to install and to replace the filter cartridge


  • Does not remove fluoride
  • Cannot be used with well water

iSpring US31

Key Features:
  • Will effectively remove sediment, chlorine, and several different contaminants
  • Keeps essential minerals and prevents bacteria from thriving in the water
  • Relatively high capacity of up to 2,000 gallons of water

Taking the 7th spot on our list is the iSpring US31 under sink water filtration system. iSpring is a famous company in the water filtration industry known for producing top-of-the-line water filtration systems particularly reverse osmosis systems and replacement parts.

The company now includes under sink water filters on their long list of products and the US31 is one of their best models that has made a significant mark on the market.

It has been built to the same level of quality we’ve seen in most of iSpring’s systems with an aim to provide a convenient and efficient way to facilitate the supply of clean, healthy water.

Filtration Performance

To start, the US31 filter system features a more standard design with 3 separate stages of filtration that work to remove a lot of harmful contaminants.

In the 1st stage, the water flows through a universal 10” polypropylene sediment filter where common sediments are cleared out down to 5 microns.

It removes sand, dust, rust, dirt, and all tiny particles which not only improves the purity of water but also helps protect and extend the life of the system itself.

The 2nd stage contains a 5-micron CTO carbon and GAC filter which is a combination that effectively removes chlorine, chloramine VOCs, and many more common chemicals that contaminate the water and cause colors, cloudiness, bad tastes, and odors. These two filters also help reduce the number of heavy metals like lead and arsenic present in the water.

From there, the water goes through another CTO carbon filter in the 3rd stage where the remaining chlorine, chloramine, VOCs, and other chemicals, as well as heavy metals, are further extracted from the water thereby improving its taste, smell, and clarity.

These three stages will remove all these contaminants without losing the minerals in the water as is the case with RO systems.

The filter is equally designed to control and discourage bacteria and parasites from developing in the water, thereby if bacterial contamination is of concern, then you are guaranteed that the filtered water produced at the faucet will be of great quality.

Capacity and Efficiency

This US31 model from iSpring is rated to provide up to 2000 gallons of water which is sufficient capacity to give you almost one year of service before you can replace the filter cartridges.

Basically, depending on the usage and water quality, you will have to change the filter cartridges every 6 to 12 months. The higher the usage and level of contamination, the shorter the lifespan will be.

The flow rate, on the other hand, can reach up to 1 gallon per minute again depending on your source water pressure.  It may not be that high, but it’s just fast enough to ensure you constantly have access to clean water on demand straight from your tap.

Installation and Maintenance

Installing and maintaining the US31 is a somewhat simple task although you may have to drill an extra hole into your countertop since it uses a separate faucet included in the kit.

If you are handy or have some basic DIY skills, it could take less than 30 minutes to set it up and the kit has everything you need including the feed water adapter, tubes, fittings adapter, a wrench, and a clear and easy-to-follow installation manual.

All three filter cartridges require replacing every 6 to 12 months and as we mentioned above, this will depend on your usage and the level of contamination of your water.

Changing the filter is as easy as installing them the first time and even much better, the 1st stage filter has a clear see-through housing to enable an easier visual inspection of the cartridge so that you can always replace it at the right time.

Moreover, the system can handle a maximum pressure of 90 psi, so the fittings are not going to blow apart and come out with the standard 60 psi municipal water pressure.

Considering that the 3-stage filtration process is highly effective in removing different contaminants and the capacity is reasonably large, the iSpring US31 is a unit that we would recommend to anyone looking for quality and reliability.


  • Will effectively remove sediment, chlorine, and several different contaminants
  • Keeps essential minerals and prevents bacteria from thriving in the water
  • Relatively high capacity of up to 2,000 gallons of water
  • Simple DIY installation and maintenance process
  • Has a clear see-through 1st stage housing for an easy visible inspection
  • Comes with a durable, brushed nickel all-metal dedicated faucet
  • Backed by a 1-year limited warranty


  • The flow rate is a bit low at 1 GPM
  • Meant for use with only municipal water

Aquasana AQ-5200

Key Features:
  • Removes over 60 different contaminants
  • Retains the naturally beneficial minerals
  • Installation and filter replacement is easy

Aquasana is another reputable brand that continues to enjoy a lot of popularity in the water filtration business and they are well known for their eco-friendly filtering options.

Their AQ-5200 is amongst the top performing under sink water filter systems on the market and the main reason behind this is the fact it’s one of the few models that have the most contaminant certifications. Here is an outlook of its major highlights and setbacks.

Filtration Performance

The AQ-5200 utilizes Aquasana’s panted and NSF certified Claryum filtration technology which is a 2-stage high-performance filtration process designed to remove over 60 common water contaminants.

In fact, it’s only a tiny handful of filters on the market that use this filtration technology which consists of activated carbon media, catalytic carbon filter media, and ion exchange.

The activated carbon filtration adsorbs organic chemicals in the water such as VOCs, MTB, herbicides, and pesticides as well as pharmaceuticals like ibuprofen and estrone.

From there, the water goes through a catalytic carbon filter where it isolates and eliminates chlorine and chloramines thereby improving the taste and color of the water.

The next filtration phase involves an Ion exchange which takes care of heavy metals like mercury, lead, and arsenic. The system is also equipped with absolute sub-micron mechanical filtration (ASMF) which helps capture asbestos plus chlorine-resistant cysts such as giardia and cryptosporidium.

The use of these different filtration technologies significantly enhances the unit’s performance compared to its competitors allowing it to remove over 97% of the contaminants in the water.

In addition to this, the AQ-5200 is certified as well to remove PFPA and PFOS, and the filtration process itself is selective hence retaining the naturally beneficial minerals resulting in filtered water that’s cleaner, healthy, and tastes great.

Capacity and Efficiency

Filtration capacity is the area that the AQ-5200 slightly falls short because it’s only capable of processing up to 500 gallons of water before requiring changing.

This is the lowest capacity on our list, but if you use the filter to process around 2 to 3 gallons every day, it will likely last up to 6 months which is fairly good.

Water flow rate is another area that this unit doesn’t really do well in as it can deliver just 0.5 gallons per minute. This only translates to a 25% increase in the flow rate compared to a normal tap and as such, you may experience a slightly slow pour but the unit is efficient.

No water is wasted and the unit can handle a maximum working pressure of 80 psi and a minimum working pressure of 20 psi.

Installation and Maintenance

You will need no plumber to set up this AQ-5200 system if you are a handy person because it’s designed for easy DIY installation with everything you require to get the job done included in the package. It comes with a separate dedicated faucet, so you will have to do some drilling if you don’t already have an extra mounting hole drilled into your sink.

Changing the filters is a snap too. No disconnecting hoses or water lines. All it takes is a simple twist to unscrew the filter housing, remove the old cartridge and insert the new one.

You only toss the filter cartridge and keep the housing which makes the replacement a bit less costly considering that the filter lasts up to 6 months.

The amazing thing about this Aquasana unit is that it’s fitted with a performance indicator which is a smart-tech system that will show the efficiency of the filter and notify you when the filter requires to be changed.

Therefore, no need to keep checking or guessing when to replace the old filters which is a big plus in terms of ensuring the system remains effective throughout in filtering out contaminants.

To sum it all, while the capacity and flow rate are on the lower end, the AQ-5200 is solid under a sink water filter system with reliable filtration technology.

The low capacity may be a deal-breaker for some but if your regular water usage is not that high and you want a unit with great filtration power that will deliver healthy clean water, then this is an option you can absolutely consider.


  • Removes over 60 different contaminants
  • Retains the naturally beneficial minerals
  • Installation and filter replacement is easy
  • Alerts you when it’s time for replacing the filters
  • Comes with a 1-year warranty and 90-day guarantee


  • Water flow is slower than most other filters
  • Low filtration capacity at 500 gallons
  • Suitable for only water with adequate disinfection like municipal water

Aquasana AQ-5300+

Key Features:
  • Highly effective filtration process for an under sink water filter
  • Removes 99% of chlorine and chloramines, and keeps essential minerals
  • Decent filtration capacity of up to 800 gallons

The Aquasana AQ-5300+ also known as 5300 Max Flow is much similar to the Aquasana AQ-5300 model but with a slightly larger capacity and faster flow rate.

However, the two models feature 3 filtration stages rather than the 2-stage process of the AQ-5200 model. In other words, the AQ-5300+ is a robust and super effective system as you are going to see below.

Filtration Performance

Like the AQ-5200 above, the Aquasana AQ-5300+ model utilizes Claryum filtration technology but with an additional stage to make it a 3-stage filtration system.

Stage 1 of the system is fitted with a 20-micron sediment pre-filter which traps silt, dirt, rust, and other visible sediments to prevent the following stages from clogging too quickly.

It’s a feature that often misses in most under sink water filters yet it’s really essential particularly in areas where the sediment and silt levels in the water are higher than normal.

Stage 2 and 3 consist of Aquasana’s Claryum filtration technology which is made up of an activated carbon filter, catalytic carbon filter, ion exchange, and sub-micron filter.

At first, the water flows through the granular activated carbon filter where a significant amount of both organic and inorganic chemical contaminants that include chlorine herbicides, pesticides, pharmaceuticals, and VOCs are removed from it along with unpleasant tastes and odor caused by these chemicals.

From there, the water goes through the catalytic carbon filtration media which is a more powerful carbon filter that clears out 99% of the chlorine and remaining chemical contaminants in the water. It also totally reduces chloramine present in the water, something that most under sink water filters cannot.

After that, the water passes through an Ion exchange filter which features a series of resin beads with a large surface area and they work effectively to extract heavy metals like mercury and lead plus other micropollutants that the carbon filters fail to catch.

At the last stage of the filtration process which is the 3rd stage, we have the sub-micron filter which clears out the remaining particles and contaminants from the water down to 0.35 microns. It will capture asbestos, chlorine-resistant cysts like cryptosporidium and giardia, and any other impurities that the earlier two stages couldn’t remove.

These three stages together will eliminate up to 99% of 77 different kinds of contaminants but leave behind healthy minerals to give you clean, fresh, and natural-tasting water.

They will also not remove other total dissolved solids (TDS) and the only microbes they can remove are cysts hence it’s not that effective for bacterial removal which simply means you should only use the unit to filter treated water that’s microbiologically safe. It’s certainly not recommended for use with well water which doesn’t contain chlorine for disinfection.

Capacity and Efficiency

While the AQ-5200 has a filtration capacity of 500 gallons and the AQ-5300 600 gallon, this AQ-5300+ model offers up to 800 gallons before a change of filters is needed. 

This slight improvement in the total amount of water it can process is mainly brought about by the larger cartridges it uses and it will allow you to utilize the unit for up to 6 to 8 months before replacing the filters.

The flow rate is equally a bit faster than that of the previous two models. They delivered not more than 0.5 gallons per minute yet the AQ-5300+ provides 0.72 GPM which is not much change but it’s significant enough to ensure you get slightly faster water flow from the faucet.

Installation and Maintenance

Hooking up this Aquasana unit should not pose a problem if you have some basic DIY skills. The installation manual explains the entire process step by step and all the necessary parts are included with the first set of filters already installed in the system.

It won’t take more than an hour to set it up but like the AQ-5200, it comes with its own dedicated faucet that you need to install, so some drilling might be involved.

Not much maintenance is required other than occasionally changing the filters at least after every 6 months and cleaning the exterior of the unit.

Another good thing is that this system too comes with a battery-operated alarm/indicator which will beep an audible alert and flash red to remind you when filter replacement is needed.

You can even link the system to your phone via Bluetooth to receive the alerts on your phone. There’s an app from the manufacturer that you can download and install for free, and keep track of the number of gallons of water that have been processed. 

Unfortunately, this app is only available for iOS devices. The indicator also uses a battery that will require changing with every filter replacement which translates to some additional costs although not very much to cause concern.

From all these wonderful features to the high filtration performance, it’s safe to say that the Aquasana AQ-5300+ is an under-sink water filter that’s worth every penny.

For those that prefer Aquasana products and the AQ-5200 model didn’t win them over, this is an alternative you might want to check out.


  • Highly effective filtration process for an under sink water filter
  • Removes 99% of chlorine and chloramines, and keeps essential minerals
  • Decent filtration capacity of up to 800 gallons
  • Fairly easy DIY installation and filter replacement
  • Monitors filter life and alert you when filter replacement is needed
  • Can be linked to a phone via Bluetooth for easy filter life monitoring
  • Comes with a 2-year warranty and 90-day satisfaction guarantee


  • Water flow rate is somewhat low at 0.72 GPM
  • Does not remove fluoride or treat bacterial contamination

Culligan US-EZ-4

Key Features:
  • Effectively removes most common water contaminants
  • Healthy minerals are not filtered out from the water
  • Simple to set up and to replace the filter cartridge

The US-EZ-4 is one of the three models in Culligan’s US-EZ series with the others being the US-EZ-1 and US-EZ-3. Among the three, the Culligan US-EZ-4 stands out the most due to its high filtration performance. This and several other nice features you are going to see are what earn it a spot on our list of the best under sink water filters.

Filtration Performance

Although it’s just a single-stage filter system, this Culligan US-EZ-4 model is equipped with a super-effective filter cartridge which is more than capable of getting rid of most of the common contaminants and impurities found in water. It offers almost the same level of filtration ability as any other top 2-stage or 3-stage under sink water filter system.

The unit utilizes a 0.5-micron high-tech carbon block filter media which has been tested by NSF International and certified to NSF/ANSI standard 42 as well as standard 53.

These certifications first mean a significant reduction of chlorine from the water. It will clear out up to 97% of chlorine along with bad tastes, odor, and turbidity, and as well remove nominal particulate class 1 which includes all particles that are as small as 0.5 microns.

Unlike the US-EZ-3 and US-EZ-1, the US-EZ-4 will also eliminate chloramines from your water which is really commendable for a one-stage unit.

Most under sink water filter systems have standard carbon filters that only filter out chlorine but will not remove the very persistent chloramine disinfectant used by municipal water treatment plants.

Besides that, this filter will remove other harmful chemical contaminants like MTBE, dozens of VOCs, and perfluorinated chemicals such as PFOA and PFOS.

The US-EZ-4 can as well remove cysts like giardia and cryptosporidium plus lead, mercury, and several other heavy metals. On average, it will reduce up to 99% of lead in the water.

As you can see, while it’s not a 3-stage system, it’s still a highly effective filter that can address many common contamination issues found in municipal water supplies.

Furthermore, it does leave behind some of the healthy, natural minerals in the water hence the water delivered to the faucet is clean and has good taste.

Capacity and Efficiency

When it comes to capacity, the US-EZ-4 falls on the lower end like the Aquasana AQ-5200 above. It can process up to 500 gallons of water which is just about average and means it will work for around 6 months depending on your usage. However, if you use not more than 2 gallons a day, it can go up to 8 months.

The flow rate is on the lower end too as it delivers 0.5 gallons per minute at 60 psi, but again if your daily water usage is not so high, then the 0.5 GPM should be good for you.

Installation and Maintenance

With a detailed DIY instruction manual and quick connect fittings, installing this unit will be somewhat easy and everything required for setup is provided.

The challenging part may be installing the dedicated chrome faucet it comes with if you don’t have a pre-drilled mounting hole as you will need to drill one.

Filter replacement is a hassle-free process since the filter head features the convenient twist on/off mechanism which allows you to change the filter cartridge within seconds without even turning off your feedwater supply. This mechanism also prevents the mess that usually happens when changing out traditional filters. 

There’s an LED filter life indicator on the faucet that automatically monitors the filter life and produces an audible sound to notify you when it’s time for filter replacement which is yet another convenient feature that simplifies the maintenance of the unit.

The connections are made of good quality plastic material and once tighten properly, they will not leak and can handle water pressures of up to 80 psi.

In general, the low filtration capacity and flow rate are the only things that may be of concern for some people, but in terms of performance and build quality, it doesn’t disappoint.

For an inexpensive and effective one-stage under sink water filter, this Culligan US-EZ-4 model is a superb deal especially if you are on a tight budget.


  • Effectively removes most common water contaminants
  • Healthy minerals are not filtered out from the water
  • Simple to set up and to replace the filter cartridge
  • LED filter life indicator ensures timely filter replacement
  • Backed by a 2-year limited warranty


  • Average filtration capacity rating at only 500 gallons
  • 0.5 GPM flow rate is a bit slower than other basic models

Filtrete Maximum (3US-MAX-S01)

Key Features:
  • Effective at reducing chlorine, lead and other common contaminants
  • Large capacity at 1,500 gallons and faster water flow at 1.5 GPM
  • Simple DIY installation as well as filter cartridge replacement

In the 12th position is the Filtrete Maximum 3US-MAX-S01 model which is the most economical pick on this list and one of the few wonderful water filters on the market that’s priced at that low.  

The unit is part of three models under Filtrete’s 3US series with the other two being the Standard (3US-AS01) and Advanced (3US-PF01) water filters. 

The major difference between these three models is their filtration capacity but the Filtrete 3US-MAX-S01 which we are going to look at below stands out in terms of getting rid of contaminants as it provides the highest rate of filtration. It’s cheaper and definitely more dependable than the other two models.

Filtration Performance

The Filtrete Maximum 3US-MAX-S01 is a simple 1-stage system featuring a high capacity filter media that has received both the NSF 42 and the much stringent NSF 53 certifications. This means it’s very capable of significantly enhancing the quality of your municipal water.

The system utilizes a 0.5-micron carbon block filtration medium which is way effective compared to basic carbon-based filters with the ability to remove 97% of chlorine taste and odor alongside other select chemicals like the pesticide toxaphene, herbicide atrazine, and select pharmaceuticals.

It has the additional capability of clearing out lead and microbial cysts (giardia and cryptosporidium) by over 90%. The filter is also able to trap sand, dirt, rust, and other particulates present in your water down to 0.5 microns which is a huge plus because a lot of other carbon filters can only reduce particles that are as small as 5 microns.

The fact that it meets the NSF 53 certification means that it’s relatively sufficient to remove VOCs and other heavy metals although not to a large extent. 

From our own assessment, we would say that this is a system that’s more geared towards dealing with heavily chlorinated water and lead, and several common city water issues as well. It’s not a unit for use with well water.

Capacity and Efficiency

We mentioned earlier that filtration capacity is the major factor that differentiates the three models in Filtrete’s 3US series. Both Standard (3US-AS01) and Advanced (3US-PF01) water filters provide a maximum of 2,000 gallons filtration capacity.

As for this Filtrete Maximum 3US-MAX-S01 model, it’s rated to process up to 1,500 gallons of water before it requires to be changed.

It’s a little lower than its counterparts but still, it’s on the higher end when you put it side to side with the other contenders herein. Even so, Filtrete recommends a 6 months replacement cycle which makes it no different from the other picks with lower capacity.

Apart from the large capacity, this unit will deliver water at a rate of around 1.5 gallons per minute. That’s faster than what many competing sing-filter systems can offer. It’s more than adequate to cater to the needs of those with regular high water usage.

Installation and Maintenance

For installing the system, it’s an easy DIY process with only a single filter to mount inside your under sink cabinet where it will fit nicely without taking up so much space. It’s extremely compact and it works with any standard kitchen faucet, so drilling is needed.

Maintaining this system is easy too. You just have a single filter cartridge to replace which should be done twice a year.

One weak point we noted though is that the unit utilizes a simple push-in design to connect the tubing to the plumbing instead of a secure compression fitting.

Therefore, the connections may possibly not be that secure and can lead to leaks in case of very high pressure. The fittings plus the faucet are made from plastic hence are also not as sturdier as the other picks that use metal.

All in all, being a low-cost under sink water filter that pretty much does its job well, the Filtrete Maximum 3US-MAX-S01 is definitely a convenient option for those that don’t want to break the bank. It will save you money and provide the necessary filtration performance to keep your tap water clean and safe.


  • Effective at reducing chlorine, lead and other common contaminants
  • Large capacity at 1,500 gallons and faster water flow at 1.5 GPM
  • Simple DIY installation as well as filter cartridge replacement
  • Takes up little space and works with existing kitchen faucet
  • Highly affordable with multiple grades of replacement filter to choose from


  • Fittings and faucet are all plastic
  • Not rated for filtering well water

GE GX1S50R Under Sink Water Filter

Key Features:
  • Good for removing chlorine taste and odor
  • Can trap nominal particulates down to 0.5 microns
  • Average filtration capacity of 750 gallons

The GE GX1S50R is a small, simple under sink water filter but packs a commendable punch as far as removing contaminants in the water is concerned. It’s an excellent choice for reducing chlorine and undesirable particles from lowly-contaminated municipal water.

Filtration Performance

Water entering the GE GX1S50R system from the cold water supply goes through a single-stage filtration process inside the filter cartridge where several different kinds of contaminants are extracted from it.

The system uses a high-quality activated carbon filtration media which removes up to 97.6% of chlorine, and negative tastes and odors. This medium is also able to clear out 99% of lead and filterable cysts like giardia and cryptosporidium.

The other contaminants it will remove from your water include turbidity, asbestos, lindane, atrazine, and heavy metals like mercury.

If your water often comes out with small particles suspended in it, then this General Electric filter will as well come in very handy.

Alongside removing most of the chemical contaminants, it’s capable of trapping nominal particulates down to 0.5 microns which clears out 98.8% of dirt, rust, sediment, sand, silt, and any other particulate present in the water.

It’s basically a dependable and reliable single-stage filtration that can supply fresh, filtered water but only for use with already treated water like from city treatment plants. We wouldn’t recommend it at all for filtering well water.

Filter Capacity and Efficiency

The GE GX1S50R filter cartridge can process a maximum of 750 gallons of water before it can be replaced. It’s a low capacity unit but if you are processing 4 gallons of water a day, then it can work effectively for up to 6 months.

 Water comes out of the faucet at a maximum flow rate of 0.75 gallons per minute which again is not that high but will do fine for low-demand usage.

Installation and Maintenance

You can successfully install this unit with some basic DIY skills. It uses a separate dedicated chrome faucet which will require drilling a mounting hole into your countertop but once you are done with that, the rest is straightforward. The filtration system is a single filter unit with a small footprint, so it will fit anywhere, even in tight spaces.

The filter head features a twist and lock design that makes replacing the filter cartridge equally fast and easy.

You will have to change it at least twice a year and to save you from guesswork, General Motors has integrated a filter life indicator with a reminder light on its dedicated faucet. It will conveniently remind you when it’s time to replace the filter cartridge to maintain the best filtration results.

Overall, if you need a water filtration system purposely for filtering out chlorine, lead, and unpleasant tastes and odor, then you may consider getting this GE GX1S50R under sink water filter.


  • Good for removing chlorine taste and odor
  • Can trap nominal particulates down to 0.5 microns
  • Average filtration capacity of 750 gallons
  • Easy to install and has low maintenance
  • Faucet features a filter life indicator
  • Comes with a 1-year limited warranty


  • Shorter filter life and low filtration rate
  • Not recommended for filtering well water

Whirlpool WHAMBS5

Key Features:
  • Rigorous filtration process removes numerous contaminants
  • Capable of removing microbiological contaminants like bacteria and viruses
  • Won’t interfere with the natural essential minerals in the water

The Whirlpool WHAMBS5 is the last model on our list but certainly not the least. Coming from a company that has been in the industry for the longest time, this model is a quality yet budget-friendly under sink water filter system that provides the necessary filtration capability to keep your municipal water clean and safe for your family’s daily usage.

Filtration Performance

The Whirlpool WHAMBS5 utilizes a 3-stage filtration process that’s certified to NSF/ANSI standards 42 and 53 to remove numerous harmful and undesirable elements in tap water.

The 1st stage is a standard 10” sediment filter cartridge with a specialized design meant to trap incredibly tiny sediments and particles from the water

It will clear out rust, dirt, silt, and other particulates down to 0.5 microns thereby preventing the filter cartridges in the following two stages from clogging.

The 2nd stage consists of a standard 10” carbon block filter cartridge which removes up to 99% of lead in the water and as well serves as the pre-filter to the 3rd stage by reducing a good amount of chemical contaminants that cause unpleasant odor and taste.

The 3rd stage features a much bigger filter cartridge compared to the other two stages and it’s the heart of the system. It holds a larger top-quality activated carbon block filtration medium that provides a higher surface area than standard carbon-based filters.

The larger surface area significantly enhances its adsorption ability allowing it to effectively eliminate greater amounts of chlorine (up to 97%) and many other chemical contaminants such as benzene, pharmaceuticals, pesticides, insecticides, herbicides, and industrial solvents. It will also clear out all the bad odors and tastes caused by these chemicals. 

Moreover, this large activated carbon filter conforms to the NSF Protocol P231 for the reduction of microbiological contaminants. Therefore, it will equally serve as a microbiological purifying filter with the capability of removing at least 99% of bacteria, microbial cysts, and viruses.

The three stages will remove all the above contaminants and much more but at the same time, it will leave the natural essential minerals found in the water giving you healthy, great-tasting purified water.

Filter Capacity and Efficiency

Whirlpool has rated this model to process a maximum of 550 gallons throughout its lifespan which puts it in the same category as the other low capacity models we’ve reviewed.

Provided you process around 2 to 4 gallons of water per day, you can expect to receive 4 to 6 months of reliable filtration performance before you replace it with a new filter cartridge.

For the water flow rate, it stands at a maximum of 0.74 gallons per minute, so also expect a moderate delivery speed, a little bit slower than that of your regular cold water kitchen faucet.

Installation and Maintenance

The Whirlpool WHAMBS5 system comes with a dedicated filtered water faucet that needs to be mounted on your countertop.

If you have an available faucet hole, you will have an easier time setting up the entire system, otherwise, you will need to drill one which is the only tricky part especially for first-timers. The unit holding the three cartridges is compact and will fit neatly in any standard-sized under sink kitchen cabinet.

You won’t break a sweat either when it comes to replacing the filter cartridges since they use a twist-in design. It requires just a simple ¼ turn to release the old filter, then pulls it out and replace it with the new one. 

You don’t need to turn off the water supply plus the faucet is equipped with an amber LED indicator that monitors the filter life after installation.

It will flash continuously once the 6 months have passed to alert you that the filter cartridges and battery need changing hence saving you from getting caught off guard. 

Though the filtration capacity and water flow rate leave a lot to be desired, we can comfortably say this Whirlpool WHAMBS5 model is a very decent and well-made under-sink water filter system. It’s a nice budget option for those who wish to enjoy safer, better-tasting water without making a big dent in their wallet. 


  • Rigorous filtration process removes numerous contaminants
  • Capable of removing microbiological contaminants like bacteria and viruses
  • Won’t interfere with the natural essential minerals in the water
  • Installation is relatively simple while filter replacement is a breeze
  • Faucet has an amber LED indicator that alerts when to change the filters
  • Backed by a 1-year limited manufacturer warranty


  • Filtration capacity is low at only 550 gallons
  • The speed of water flow is low too at 0.74 GPM

Under Sink Water Filter

While the water from most city treatment plants may be safe when it comes out of the factory, there’s always a real chance it can pick up different kinds of contaminants along the way as it moves in the old pipes.

When you dispense it from your tap, it’s likely to have numerous contaminants like lead, chemicals, and organic compounds which can cause health problems either in the short term or long term.  

The good news though is that water filtration technology has advanced to the point that most contaminants that were previously removed by only reverse osmosis systems are now able to be blocked by under sink filters.

Under sink water filters have become more efficient than ever allowing you to take control, minimize and even eliminate the risks posed by the contaminants in the water coming out of your tap.

Feel free to read away to get the whole picture about under sink water filters and see which one will fit your expectations.

An under sink water filter is a water purification filter designed to sit underneath the kitchen counter, right underneath the sink itself and it’s connected directly to the under-sink cold water supply where it takes water from and sends it to a filtration media for purification after which it’s sent directly to a faucet for instant dispensing. 

best under sink water filter

Benefits Of Using An Under Sink Water Filter

There are plenty of benefits to using an under sink water filter to purify the water that’s delivered to your sink for drinking or cooking. Here are some of the key ones:

Removes A Wide Range Of Contaminants

Unlike the old models which used to use only an activated carbon filter media, modern under sink water filters today combine more technologies that enable them to remove a wide range of harmful contaminants that only the full RO systems could deal with.

The most common contaminant that these filters are very effective at removing chemicals particularly chlorine and chloramines. They are eliminated by the activated carbon filtration media and most under sink filters at least have one. This media is really good too at getting rid of bad tastes and smells from the water.

Under sink water filters can as well block heavy metals by either using a KDF carbon filter combination or a treated activated carbon filter.

There are also some models that are able to eliminate fluoride and arsenic from the water using a special Alumina filter although this removal is usually not 100% complete.

Nitrite/Nitrate, limescale, sediment, and microorganisms are some of the other impurities that under sink water filters can block from reaching the faucet.

No Wastewater

While many RO systems produce wastewater with some even flushing up to 4 gallons of wastewater per day down the drain, under sink water filters don’t generate any wastewater.

It’s connected directly to the under sink cold water pipe and to its own faucet or an existing one, so basically, it produces clean, filtered water without giving out wastewater. Water goes into the filters and leaves through the faucet once purified.

Water on Demand

The other major benefit is that you don’t have to sit and wait for the tank to fill up before being able to dispense water like in the case of an RO filtration system. With an under sink filter, you get clean, filtered water straight from the faucet whenever you need it.

Saves Space

With no additional components such as storage tank and water pump, under sink filters don’t need much space like RO systems or whole house filtering systems.

In fact, they won’t take one square inch of your countertop space as they go completely under the sink in your kitchen cabinet. Most only require a little space in the cabinet which is convenient if your kitchen is small.

Under Sink Water Filter Working Process

Understanding how an under sink water filter works is essential when you are looking to buy one as it allows you to easily identify the differences between models and builds.

In general, under sink water filters come in two types. On one hand, we have the simple under sink filters while on the other we have the conventional under sink filters.

The difference between the two types is basically the faucet. A simple type under sink filter utilizes the existing faucet already installed within the sink unit whereas a conventional type filter will need a faucet of its own which is usually provided alongside the system. 

Therefore, how do these filters work?

Well, an under sink water filter basically takes water from your cold water supply under the sink and diverts it to the cartridge where the filtration media stays. Inside the cartridge, the water is passed through the filter media where it’s stripped of different kinds of impurities.

Each model utilizes different variations of filtration media. Some utilize a simple 1-stage process while others feature up to 3 stages of filtration.

However, the most important filtration media in many under sink water filters is activated carbon. Most filters have at least one which effectively removes chemical contaminants like chlorine, volatile organic compounds (VOCs), and chloramines

Some models utilize two carbon filters, an initial one for trapping most of the chlorine, chemicals, and larger contaminants and a second one to ensure the remaining chemicals contaminants are cleared out from the water.

The most advanced units incorporate UV light sterilizer to thoroughly clean the water and there are even models equipped with a remineralization filter to provide filtered alkaline water.

Once the water is sufficiently purified by the filter, it’s sent out to the faucet on the sink where it’s dispensed for consumption. The process happens on-demand, so no wastewater is generated and it works completely by water pressure.

For a simple under sink filter, the water will be delivered through your regular faucet. You will only have one cold water faucet and one hot water faucet if you have it installed.  Only the water from your cold water line gets filtered not the hot water.

For a conventional filter, once the water is filtered, it’s directed to a dedicated faucet mounted on the sink. This faucet is independent of your regular kitchen faucets for cold and hot water, and you have to install it.

Therefore, you get to still use the two regular faucets separately and benefit from the filtered water from the unit for cooking or drinking.

Installation and Maintenance

Under Sink Water Filter Installation

Installation of under sink filtration systems is usually easy and straightforward. The filter is installed inside the cabinet underneath your kitchen sink.

You may, however, be required to drill a hole on the sink if you are installing a conventional under sink filter to accommodate the faucet it comes with. This is if you don’t already have one spare hole.

The following procedure is for setting up a conventional under sink water filter and can be used for the installation of simple under sink filters too without the drilling part.

  • First, drill a ½” hole on the spot you want to mount the faucet using a masonry drill bit.
  • Insert the faucet and secure it into the hole while ensuring it’s properly aligned in the right spot. (Check our RO system installation article for detailed steps for installing an RO faucet)
  • Once the faucet is installed, turn off the cold water supply under the sink and drain the water inside the line.
  • Mark the location where you want to place the filter inside the under sink cabinet.
  • Screw the filter into the mounting location and perform all the necessary plumbing connections. Most models will have a mounting bracket to allow you easily attach the filter to the cabinet wall.
  • Install the fitting to your cold water supply line and connect the tubing from the under sink water filter to the fitting and then to the newly installed faucet.
  • For the simple under sink filter type, there’s no separate dispenser, so simply connect the filter directly to your cold water line and the existing cold water faucet.
  • Test the new filter to see all the connections are good and then leave the filtered water to run for about 5 minutes before using it.

Every model will come with its own installation procedure. You should ensure to follow the manufacturer’s instructions manual to prevent encountering any difficulties.

Under Sink Water Filter Maintenance

Like any other water filtration system, an under sink water filter requires regular maintenance which involves cleaning and changing the filter cartridges after a certain time scale depending on your usage and quality of your incoming water.

There’s no general timeline on when to change the filters as their lifespan will vary from one different brand to another. 

However, most models require changing once every 6 months. There are several models that can last up to 1 year while a few others can go for up to 5 years before requiring replacement.

Below is a basic process for replacing an under sink water filter cartridge although it may vary based on the model you have:

  • Turn off the cold water supply and open the faucet to drain all the water in the system
  • Using a screwdriver, housing wrench or the tool provided by the manufacturer, open the casing and remove the filters.
  • Nicely clean the casing and then insert the new filter, and close the casing well.
  • Once everything is set, turn on the water and check for leaks. If there are none, let the water run for 5 minutes before you use it.

NOTE: All the filters should be replaced at the same time even if some look better than others to ensure the system performs efficiently.

Advantages and Disadvantages

As much as under sink water filters have nice qualities, we believe it’s good to also be aware of all the pros and cons of these products so that you remain critical when making your final decision.

Advantages of Under Sink Water Filters

  1. Effectively improves the water quality – whatever contaminants you are concerned about, there’s an under sink water filter that can deal with them. You can select the filter according to the type of contaminants you are more concerned about.
  2. Makes the water taste and smell much better – all under sink water filters often have an activated carbon filter which eliminates most of the chemicals and unpleasant odors hence improving the taste of the water and making more pleasant to drink. 
  3. Filtered water on-demand – there’s no waiting for water to dispense with an under sink filter as the water is delivered instantly unlike in RO systems. You just turn on the faucet and get clean filtered water instantly.
  4. Save countertop space – under sink filters are usually much compact in size and they don’t need a lot of space inside the cabinet. It not only leaves enough room to store other items but you also get to save your precious countertop space.
  5. Easy installation and low maintenance – setting up an under sink water filter unit requires minimum capabilities. You don’t need any special skills and there several simple DIY videos throughout the internet to show the process. Changing the filter elements after a certain period is also the only maintenance you will have to do.
  6. Good value – the purchase price of these filters is not high compared to basic RO systems. Plus the maintenance cost is low too since the replacement filters are affordable and usually last a long time, so you save a good amount of money in the long run since you don’t have to replace the filters as often.
  7. A variety of options to choose from – there is a wide range of under sink water filters out there to meet the needs of each user depending on the kind of contaminants you want to remove. There are standard models and even more advanced options with several filtration stages to deal with stubborn and persistent contaminants.

Disadvantages of Under Sink Water Filters

  1. May need a separate faucet – conventional under sink water filters utilize their own faucet provided by the manufacturer. This faucet is independent of your regular kitchen faucets and requires installation hence you may have to cut an extra hole into your sink.
  2. Depends completely on water pressure – under sink water filters work completely using the source water pressure. Therefore, any drop in the water pressure going into the unit will certainly lower the rate of filtration and production of purified water at the faucet.


An under sink water filter provides a convenient and much affordable way of getting an instant supply of clean and healthy water. They are best for purifying municipal water with fairly low levels of contamination which doesn’t require an RO system to remove.

The above-mentioned models have impressive filtration performance and can address various kinds of common tap water issues. However, your choice will depend on the particular contaminants you want to remove from your water as well as the capacity.

You should go for a high-capacity system that has a faster flow rate and a long-lasting filter that is easy to replace. CuZn UC-200 and Woder WD-S-8K-DC models are some good examples.

All in all, whatever unit you pick, make sure to confirm that it’s certified and capable of removing the contaminants that are often present in your water, and require minimal maintenance. We’re certain that with our reviews above, you will find it easier to make an informed decision and pick the best model for your household.