The 10 Best Under Sink Water Filters (Reviews & Comparison 2018)

You have surely seen those magazine photos of kitchen sinks with two faucets. Well, now it is time to reveal the secret as to why some households have 2 faucets installed on the same sink. It’s because the second unit is for purified water only.

There’s nothing incredible here. The only impressive thing is how purified your water will be if you get the best under sink water filter on the market. We can’t tell you which one it is exactly because this comes down to personal preference and needs. What we can do is simply guide you through the process of selecting the best unit for your family.

In our expert under sink water filter reviews, you will find plenty of information regarding how exactly these devices work and what is their main purpose. We have also added other informative sections on the various types of filters accompanied by a quick installation guide. Why spend any money before getting the whole picture? Feel free to read away!

  • 4.3 Customer Rating
  • Filtrete Advanced Under Sink Quick Change Water Filtration System
  • PRICE $
  • Dimensions : 4 x 6.8 x 14"
  • Weight : 6.26 pounds
  • Filter Life : 2000 gallons or 6 months
  • Flow Rate : 1.5 GPM
  • Pressure : 25-125 PSI.
  • 4.9 Customer Rating
  • CuZn UC-200 Under Counter Water Filter
  • PRICE $$$
  • Dimensions : 4.5 x 4.5 x 15"
  • Weight : 8 pounds
  • Filter Life : 50,000g or 5 years
  • Flow Rate : 2 GPM
  • Pressure : 130 PSI max.
  • 4.6 Customer Rating
  • Woder 10K-Gen3 Ultra High Capacity Direct Connect Water Filtration System
  • PRICE $$
  • Dimensions : 3 x 3 x 15"
  • Weight : 2.75 pounds
  • Filter Life : 3 years or 10 000 gallons
  • Flow Rate : 2 GPM
  • Pressure : 60 - 125 PSI
  • 3.9 Customer Rating
  • Culligan US-600A Undersink Drinking Water Filtration System
  • PRICE $
  • Dimensions : 4.8 x 4.8 x 12.8"
  • Weight : 1.74 pounds
  • Filter Life : 1 year or 1 000 gallons
  • Flow Rate : 1 GPM
  • Pressure : 60 PSI
  • 3.8 Customer Rating
  • Aquasana 3-Stage Under Sink Water Filter System with Brushed Nickel Faucet
  • PRICE $$$
  • Dimensions : 12 x 4.2 x 9"
  • Weight : 7 pounds
  • Filter Life : 6 months or 600 gallons
  • Flow Rate : 0.5 GPM
  • Pressure : 20 to 80 PSI

Best Under Sink Water Filters 2018

The first section that we have prepared for you will take you straight to the finest products available. Our experts have come up with short write-ups on these units. They are sorted in no particular order so just check them all out and see which one is good for you.

1. Filtrete Advanced Under Sink Quick Change Water Filtration System

Filtrete Advanced Under Sink Quick Change Water Filtration SystemWe kick off our review sections with a product which will not set you back a lot of money. However, the Filtrete Under-Sink Quick Change Water Filter is an efficient gadget with plenty of merits. You can count on it to remove about 99% of protozoa and bacteria. The same goes for cysts, sediment, and some solids. What’s really good is that you won’t feel any chlorine taste in your water because 96% of it will be gone. A little bit on the downside, the water flow is not impressive. You will get about 1.5 GPM and if you want this rate to improve, you will need to invest in a water pump separately. No special tools are required for the installation of the unit. All you need is a screwdriver and a wrench. The rest is provided by the manufacturer. You can expect to change filters once every 6 months or so.

Read more about Filtrete Advanced Quick Change

2. CuZn UC-200 Under Counter Water Filter

CuZn UC-200 Under Counter Water FilterThe capacity is the definite selling point of this next filter. Its proprietary technology allows it to generate about 50 000 gallons of fresh water. This astonishing number will be covered in about 5 years of use. It all comes down to what’s inside the filter. There we find a special micro sediment membrane accompanied by a KDF-55 Coconut Shell Carbon. This combo will prevent all sorts of lead, nickel, chromium and other metals from entering your drinking water. There is one picky aspect, though. And it’s about the nature of the water you are going to be using. It can’t be well water, only a municipal one. The flow rate is 2 GPM which is pretty impressive for such a thorough filtration system. Tech support is always at your disposal in case you got questions regarding operation and installation. Both are pretty easy to deal with so just check the instructions.

Read more about CuZn UC-200

3. Woder 10K-Gen3 Ultra High Capacity Direct Connect Water Filtration System

Woder 10K-Gen3 Ultra High Capacity Direct Connect Water Filtration SystemThat’s versatile under sink filtration system which will also be quite budget friendly. You can have it installed not only in your kitchen but in your RV as well. The fact that this is a cheaper product doesn’t mean that it lacks quality. The unit is fully NSF certified and will get you clean water for a long time. What is not very convenient is the fact that the filter works with municipal water only. You can’t hook it up to any well water supply. Additionally, hot water is incompatible with the technology of the unit. In that sense, the recommended temperature of the water is between 43 and 100 degrees. The filter is advertised to have a PSI of 125 but 60 sounds more realistic. With moderate use, the filter should last for about 3 years or 10 000 gallons of water. You will struggle to find an under sink filter with easier and quicker installation.

Read more about Woder 10K-Gen3 Ultra High Capacity Direct Connect

4. Culligan US-600A Undersink Drinking Water Filtration System

Culligan US-600A Undersink Drinking Water Filtration SystemWhat you get from this bare-boned filter is decent functionality and clean water. That’s a nice budget option for any household as the unit will simply get the job done with no extra fluff. It is USA-made and covers all NSF/ANSI standards. You can expect odorless, tasteless water with no chloramine in it. A huge advantage is the compatibility of the system with various filters including D-10A, D-20A, D-30A and so on. The life of the actual filter is shorter compared to some other units on our list but is definitely satisfying. You should have clean water for 1 full year before having to replace the cartridge. No hot water should pass through the system as the maximum temperature is 100 degrees. There’s no need to use an additional faucet with the filter. The manufacturer has also already assembled most of the system for you, so you just need to snap it under the sink and connect the lines.

Read more about Culligan US-600A

 

5.  Aquasana 3-Stage Under Sink Water Filter System

Aquasana 3-Stage Under Sink Water Filter System with Brushed Nickel FaucetHere we have a system which incorporates 3 filters. Your water will go through 3 cartridges before reaching the faucet meaning that it will definitely be thoroughly filtered. The Aquasana 3-Stage Under Sink Filter cannot substitute a reverse osmosis system but it definitely gets close to it. It is good for both well and municipal water. As expected, the first stage features a 20-micron filter which will take care of the “big boys” such as dirt, sediment, sand, etc. Then comes the activated carbon filter which will render your water chlorine-free. That’s where pesticides, viruses, and herbicides are also gotten rid of. Lastly, the water passes through a catalytic carbon filter which uses ion exchange in order for heavy metals to be reduced. A slight drawback is that the life of the filters isn’t huge – 6 months at best. The flow rate is also abysmal as it stands at 0.5 GPM.

Read more about Aquasana 3-Stage

  • 4.5 Customer Rating
  • APEC WFS-1000 Super Capacity Premium Quality 3 Stage Under
  • PRICE $$$
  • Dimensions : 18 x 12 x 10"
  • Weight : 14 pounds
  • Filter Life : 12 months
  • Flow Rate : Designed for up to 5gpm
  • Pressure : 20 - 85 PSI
  • 4.3 Customer Rating
  • iSpring US31 3-Stage Under Sink High Capacity Tankless Drinking Water Filtration System
  • PRICE $$$
  • Dimensions : 16 x 6 x 16"
  • Weight : 13.45 pounds
  • Filter Life : 2.000g or 1 year
  • Flow Rate : 1 GPM
  • Pressure : 90 PSI max.
  • 4.5 Customer Rating
  • Ecosoft 3 Stage Under Sink Water Filtration System
  • PRICE $$$
  • Dimensions : 16.5 x 6 x 14.6"
  • Weight : 8.4 pounds
  • Filter Life : 6 months
  • Flow Rate : 0.25 GPM
  • Pressure : 87 PSI Max.
  • 4.1 Customer Rating
  • Culligan US-EZ-4 EZ-Change Undersink Drinking Water Filtration System
  • PRICE $$
  • Dimensions : 3.8 x 9 x 14"
  • Weight : 4.1 pounds
  • Filter Life : 6 Months or 500 gallons
  • Flow Rate : 0.5 GPM
  • Pressure : 60 PSI
  • 3.9 Customer Rating
  • 3M Aqua-Pure Under Sink Water Filtration System
  • PRICE $$$$
  • Dimensions : 22.5 x 4.9 x 4.7"
  • Weight : 4.75 pounds
  • Filter Life : 6000 gallons
  • Flow Rate : 2.5 GPM
  • Pressure : up to 125 PSI

6. APEC WFS-1000 Super Capacity Premium Quality 3 Stage Under

APEC WFS-1000 Super Capacity Premium Quality 3 Stage UnderThis is one more US-made product with nice characteristics at a decent price. The APEC WFS-1000 is a WQA certified system which allows for a constant supply of filtered water. Even though there’s nothing special about the dimensions of the cartridge, the unit will do a good job filtering out sediment and other contaminants. The 2×10-inch filter is actually an extruded carbon one. This means that the media which is trapped inside the filter will never get to your drinking water. This also reduces the time required for flushing the system upon replacing your filter. Fluoride cannot be removed by this system. Heavy metals will also remain there which is kind of a letdown.  Bear in mind that you will need to drill a hole in your sink in order to accommodate the additional faucet for the system. The instructions are pretty clear but you might fancy seeking some tech support from the manufacturer as well.

Read more about APEC WFS-1000 Super Capacity

 

7.  iSpring US31 3-Stage Under Sink Filtration System

iSpring US31 3-Stage Under Sink High Capacity Tankless Drinking Water Filtration SystemWe simply cannot let you go without showing you another 3-stage filtration system. The iSpring US31 can definitely give any reverse osmosis system a run for its money although the micron rating cannot be compared at all. Here you get 3 filters all of which have a 5-micron rating. If this doesn’t sound right for you, then you are free to buy replacement filters of other micron rating but this will cost you. Other than that, the dimensions of the filters are standard – 2×10 inches. The purity of your water will not below. On the contrary, 5 micron is a decent rating and you can expect rust, sand, dirt and other particles to be removed. No TDS will be taken care of and that’s something to keep in mind when buying. The filters will likely die every 2000 gallons which should be about once every year. Don’t expect wonders from the 90 PSI. You will likely get nothing more than 1 GPM.

Read more about iSpring US31 3-Stage High Capacity Tankless

8. Ecosoft 3 Stage Under Sink Water Filtration System

Ecosoft 3 Stage Under Sink Water Filtration SystemAn interesting mixture is observed when we talk about the Ecosoft 3 Stage Under Sink Water Filter. It is a compact unit suitable for your bathroom, kitchen or even RV. On the other hand, it can handle a big workload and this makes it a popular choice. It should be noted, however, that high demands typically mean shorter filter life. Ideally, you should be able to get about 6 months out of each filter. During the first 30 days after the purchase, you are free to return the product as it has a money-back guarantee. Now as far as the specs of the system goa, there’s nothing mind-blowing about them. The new faucet that you will have to install will yield fresh water at a rate of only 0.250 GPM. This is by far the lowest GPM on our under sink filter reviews section. Read the installation instructions carefully as there might some underwater rocks there.

Read more about Ecosoft 3 Stage

9. Culligan US-EZ-4 EZ-Change Undersink Water Filtration System

Culligan US-EZ-4 EZ-Change Undersink Drinking Water Filtration SystemPlain and simple you will have chlorine-free, odorless and tasteless water if you opt for the Culligan US-EZ-4 Undersink Drinking Water Filtration System. It features just 1 filter which should be good for about 500 gallons. Unlike systems which have 3 stages of filtration, here you can pretty much only expect for the unit to remove chlorine and a few other contaminants. At least that’s what the factory filter does. You have the freedom to use a different cartridge with the same system which is a big advantage. There is a LED indicator which will prompt you to replace the filter when the time comes. If you have massive demands for fresh water, this device might not satisfy them. The GPM is only 0.5 and the pressure is only 60 PSI. The installation is not going to be very hard but the connections might leak. Make sure you tighten them nicely.

Read more about Culligan US-EZ-4 EZ-Change

10.  3M Aqua-Pure Under Sink Water Filtration System

3M Aqua-Pure Under Sink Water Filtration SystemNow here’s an under sink water filtration option which comes at a price. The 3M Aqua-Pure Under Sink Water Filter will set you back a more serious amount of money but will get you 6000 gallons of cleansed water before a filter change is needed. The moment you see the cartridge, you immediately realize that this is a high-quality product with exceptional features. It will give you quick flow rate – 2.5 GPM and will work at a higher pressure – up to 125 PSI. Even though lead and other harmful chemicals will be removed from your water, calcium and some other beneficial substances will remain intact. A slight knock is that the unit features 3/8-inch NTP connection fittings. If your lines are ¼-inch ones you will need to get adapters from the local hardware store. The Sanitary Quick Change technology allows for a painless and hassle-free replacement of the filter.

Read more about 3M Aqua-Pure

The Benefits Of Under Sink Water Filter Systems

Under Sink Water Filter System Reviews

It is pointless to even discuss all the threats that tap water holds for us and our families when it comes to healthcare. In this guide, we will focus heavily on under sink water filter systems and will not waste a lot of time listing all the important contaminants that you can find in the municipal water.

Instead, we will talk about all the cool advantages that you can get from an under sink water filter. There might also be a few drawbacks so we will outline them as well. The benefits can be divided into two main categories:

  • Health-related
  • Product specific

Our Health Matters The Most!

The first group of benefits is related to the general functionality of the water filtration systems of any kind. Here we will talk about the main contaminants that will be removed from your water.

  1. First of all, the most popular contaminant in your water is likely chlorine. While it is meant to actually kill bacteria and disinfect your water, chlorine is also not very good for your health. Chloramine, which is its main component, will make water taste and smell pretty bad.

 

  1. All other sorts of chemicals can also be found in your municipal water supply. Pesticides and herbicides are a huge problem in some areas and having a decent water filter under your sink will surely have a positive impact.

 

  1. Fluoride is one of the greatest threats you will find but it also has a number of benefits attached to it. It is a very controversial addition to municipal water and some countries have already banned it. Others still use it heavily. Fluoride’s main purpose is to make teeth better. On the downside, it makes our health worse in general.

 

  1. Heavy metals and lead. There’s a difference between the two but they are both not alright to drink. Lead rarely comes from your municipal water supply. It actually comes from your own piping and plumbing installation. As tubes age, they start releasing lead. The same goes for faucets.

Heavy metals come from local industries. Typically, the waste which is thrown away ends up in our water. Examples of heavy metals are iron, mercury, and cadmium. Needless to say, you should not drink that.

  1. Microorganisms and viruses are also something to watch out for. Diseases are easily spread through tap water and by filtering it you can significantly reduce this possibility. It will likely come to no one’s surprise that microorganisms usually come from animal and human waste.

Among the more popular diseases, we can list cholera, typhoid, and hepatitis. While all three are curable, they can be quite dangerous.

Physical Advantages Of Undersink Water Filters

A closer look at our 2018 under sink water reviews reveals that this sort of devices has a number of other advantages not related to water purification. These upsides are all about what you get from the product that you have just bought.

So the water is safer to drink and it has a better taste – we already got that out of the way. Along with that, though you need to realize that your water’s quality actually improves significantly and that’s important. It is better for children and allows them to grow up healthy.

Additionally, cooking is now going to be a very safe activity when it comes to the composition of your food. All in all, you will notice an improvement in your health as filtered water is great for:

  • Drinking
  • Cooking
  • Washing
  • Cleaning

You will not need any extra space when installing an under sink water filter at home. As the name shows, these things go in the cabinet under the sink and are practically invisible for everyone. They can be installed right on the sides of the cabinet thus allowing you to continue to use it. You will have to give up very little space for an under sink filtration system.

What’s more is that your countertop will be absolutely free and available for you to use however you see fit. Unlike countertop filters or **maybe even water filter pitchers** here you do not need to make any compromises with where the device will fit.

Installation is also typically rather easy. While some advanced systems require a little bit more connections, a common under sink filter will have just 2-3 tubes to connect. Once you are happy with how the casing is attached, you will be good to go.

Another cool advantage is cost-efficiency. At the end of the day, you will be able to save a little more because such a filtration system is not the most expensive one. If you go out looking for more advanced units, then you will surely pay more. Here, you get enough filtration without having to pay a lot. To be honest, you can get an overall cheaper option such as a fine water distiller but it is questionable exactly how effective it would be.

The variety is one good argument as well. Users get to select from a wide array of water filtration options when it comes to cartridges. Some cost more than others but it all comes down to the type. You can even string a few cartridges together in order to achieve more thorough filtration.

Once you start using an under sink water filter, you will find out that there’s not much to it when it comes to maintenance. Yes, the cartridges will come at a price but you will change them once every few thousand gallons or so. Additionally, replacing filters is not a grueling task and it will require no special skills. All you need to do is follow instructions.

But What’s On The Downside?

An argument against under sink water filter systems is that you get to use them only at one location. You will get purified water from just one faucet. This means that all other water outlets inside of your home will still have regular tap water.

This is usually not recommended especially for families with a few children. If you wish to cover all the faucets and showers at home, then you will need to look into some other top class water filtration options.

A little bit of a hassle will be added by the fact that you will also have to install a separate faucet. This is not imperative but it is definitely recommended. Having a separate faucet installed is good for two reasons:

  • As this is a fresh addition to your plumbing, it will not have any rust and will not generate any lead. A brand new faucet will not have any buildup meaning that your already filtered water will pass through a very clean area on your way to your glass.
  • It allows you to separate your filtered water from the other one without the need to use a bypass valve.

Now that we’ve covered the advantages and some disadvantages of under sink filtration systems, we can dive into the more specific stuff.

Type Of Filters To Install Under Your Sink

best under sink water filterThe products that we are talking about in this guide are part of a very broad class. As seen in our under sink water filter reviews, there are systems with 3, 4, 5 or more cartridges connected to each other. We also have specialized under sink water filters for well water in particular. All of this goes to show you that depending on the type of water that we have (and other factors too) we have to select the proper cartridge.

Here we will talk about the wide variety of filters that can be found on the market nowadays. They differ in a number of ways from one another. It will all become clear to you once we start talking about size, functionality, purpose, longevity and of course, price.

Is Classic Always Best?

The String filter is the classic choice and it is pretty much the oldest one when it comes to innovation and technology. The name shows you exactly how the filter is composed. It is basically a core with some string wrapped around it.

The tighter the string is coiled, the smaller the micron rating will be. As far as the size goes, you got 2 options here in the general case. The width is always the same – 2.5 inches. Length, on the other hand, can be either 10 or 20 inches. That’s a standard size for pretty much any filter.

There are larger string filters, of course – 4.5 x 10 inches and 4.5 x 20 inches. In fact, you will be able to find even some quirkier sizes in case you look hard enough. But for residential use, these are the most popular options.

String filters are a common thing and the popular opinion is that they last a long time. Yes, they do and that’s because they simply do not filter that well. Tests show that when water with lots of solids is run through a string filter, not a lot of these solids are trapped inside. Actually, string filters fare pretty badly in comparison with other filters when it comes to the ability to trap these dissolved solids.

Pleated Filters and Their Effectiveness

Solids are going to be trapped easily if you use a pleated filter. These cartridges are wrinkled and their surface resembles a harmonica. These are also good in the role of a whole house filter. In this case, you might have to go to a pretty big housing. We are talking about a cartridge with dimensions of 4.5 x 20 inches.

Here we have a sheet of media which is pleated and wrapped around a core. Actually, the media itself might be about 26 feet long. So you can imagine how tightly it is wrapped. Unlike string filters where the surface expands when wet, with pleated filters you have a media which always retains its shape and size. This allows it to trap:

  • Dirt
  • Sediment
  • Sand
  • Other particles

In short, your under sink water filter will be fantastic with a pleaded media when you want to filter well water. Such a filter creates natural barriers which won’t allow solids to pass through. A slight knock is that pleated filters will have a shorter lifespan but they can handle higher water flows. Besides, larger filters are replaced less often.

In terms of material, you do not want to have a paper filter. The best option here is the pleated polyester surface. It doesn’t degrade easily and will last longer than usual. Be aware that washing the filter off isn’t a great idea.

One of these filters, even the large ones, are not very expensive. So buying one shouldn’t be a huge issue. Don’t be stingy about it.

Melt Blown Filters

The other name of this filter is a spun polypropylene filter. The main feature here is that it is a gradient density filter. This means that the outer layers of the surface have a higher micron rating and as we move closer to the core, the microns start to decrease.

So it can start with 30 microns and go down to 5 or 1. In other words, here you have a filter that can be used instead of stringing 2-3 cartridges of different micron ratings. This makes it perfect for point of use systems such as under sink water filters.

If you go with this filter, you will not need to think about getting a few cartridges and connecting them in order to get more filtration. The membrane here will gradually become denser and will eventually stop exceptionally small particles.

The top US-made brands often make these filters with little grooves. This way they give you about 40% surface area and the grooves serve as a natural barrier against contaminants.

Carbon Filters

These filters have been around for some time. They utilize granular activated carbon as a filtration method. What’s not so cool is that you get a lot of carbon fines. The water might even turn black for a while.

However, these filters have received significant improvements over the years and now the extruded carbon block filters will not let any media infiltrate your drinking water. The larger filters of this type (typically the 4.5 x 20-inch ones) weigh about 7 pounds. That’s how you can determine their quality because most foreign-made units weigh just 3-4 pounds which is insufficient.

There is one more sub-type here which deserves just a little focus as well. It’s the media filters which use various substances for filtration. Some might have resin in there, others – coconut shell. What you have to look for here is the craftsmanship. You want sonic-welded media filters because otherwise you will see particles in your water and that’s a big “no-no”.

The New Boys On The Block

The newest members of the filter family are the pulsar disrupter filters. These are media units that use electroabsorption. They somewhat look like pleated filters but the fibers have a zeta charge. So the filter has a micron rating of about 3-4. In reality, though, you will get water filtration down to 0.5 microns or even less.

Some of the more important things that are taken out by the zeta charge are:

  • Bacteria
  • Chromium six
  • Lead
  • Viruses
  • Cysts

It’s best if you get a filter with a double O-ring. The tubes just snap on to the fittings and that’s it. Both ends of the cartridge will be sealed properly and no leaks are to be expected.

Micron Ratings

People rarely realize what is the difference between the various micron ratings when in fact, it is pretty simple. We hear that a filter is a 5-micron one while another is a 10-micron one. So here’s how to easily remember what this feature means.

The larger the micron rating, the less this filter will take out. So a 50-micron filter will be good only against the largest particles in your water. A 5 and 1-micron filters are exponentially more thorough in that regard.

Then, you can move to sub-micron and really start talking about trapping small particles. There are ½ micron filters and even 0.35 ones. So which one is good? The one with the smallest micron rating? Perhaps looking for a middle ground is the way to go.

 

 

50-micron filters will survive for a long time and you will rarely replace them. They will also allow for a faster water flow but you will not enjoy the cleanest of water. A 1-micron filter will die quicker and your water will pour very slowly. You will have purified water but you must also be ready to replace your filter relatively often.

Most experts, including ours, will recommend getting a 5-micron filter for your domestic or even business needs. Sometimes what is required to be done is the so-called step-down filtration. That’s when you basically string together 2 or more filters in a row. That’s good if you have a lot of:

  • Sediment
  • Silt
  • Cloudiness
  • Sand

For instance, you would start with a 20-micron filter, then have a 5-micron one and finally, the water will go through a 1-micron filter. Those values may vary depending on your particular needs as well as the number of cartridges that you will be using.

Installing Your Under Sink Water Filter

INSTALLING YOUR UNDER SINK WATER FILTERUnless you buy any type of countertop water filter, you will need to deal with some sort of installation in order to get purified water. This case is no different as under sink filtration indeed has to be mounted.

Luckily, very few things are challenging and the better part of the process is exceptionally similar to any general whole house water filter installation. The main difference is that here we are mounting a point-of-use device meaning that we are not going to interfere with the plumbing of the whole house.

So before you get started, make sure you have most of the following tools and supplies:

  • A tubular wrench
  • Drill with drill bits of at least 2 sizes
  • Screwdriver
  • Ruler
  • Tape measure
  • Pen

As expected, you should start by shutting off the cold water valve. You should also open the faucet in order to relieve any remaining water pressure. Disconnect the soft connections found under the sink. Use one of the wrenches if needed. Don’t worry if a little water comes out.

Next comes the drain pipe clamp. The rubber ring also known as gasket must go inside the clamp. Then the whole thing is screwed on to the inlet under the sink. That’s the pipe that you just freed from the soft connection.

Now the soft connection goes into the clamp. Make sure that the gasket doesn’t fall off the fitting. If it is old and rusty, you should replace it with a new gasket. Tighten these connections well – you don’t want to risk any leaks. This is where you can conduct a mid-way check. Turn the cold water supply valve on and open the faucet. Check for leaks.

Now the putting the faucet might cause a little trouble and it is best if you know what you’re doing. Assemble the faucet and tuck in the decorative stand. Insert the rubber casket into the faucet base and only then but the whole stand on. Do all of this before installing the faucet on to the sink because otherwise, the stand will not fit.

Drilling the hole in your sink needs to be done impeccably. Use the drill and the proper drill bits for that purpose. Once you insert the faucet, tighten it with the nut and the bolt. This is done under the sink, of course. Use your tubular wrench for maximum effectiveness.

The tube must have a nut on. Tuck the tube into the faucet from underneath the sink. Tighten the nut using your fingers initially but going back to the wrench after it becomes tougher to screw. Do the same with the inlet pipe and the clamp. The only difference is that you won’t need a nut there. Just a little plastic clip which should be included.

It is now time to actually attach the filter itself to the walls of the cupboard. Here your little 3mm drill bit will come in handy. Make the necessary measurements and drill the holes. Follow the instructions because every filter has different dimensions and the locations of the holes will vary.

Some under sink filters come fully assembled. In this case, you will not have to put the cartridges on the casing. Only two things are now left to do:

  • Attach the casing to the wall
  • Connect the tubing to the filters

There is no particular order in which these must be done. Some prefer connecting the tubes now because otherwise, the inlet on the inside of the cupboard will be hard to reach. Once you are happy with how solid everything is, just turn on the water supply. Don’t forget to flush according to the manufacturer’s instructions.

Best Under Sink Water Filter Comparison Chart

PRODUCTPRICEDIMENSIONSWEIGHTFILTER LIFEFLOW RATEPRESSURE
Filtrete Advanced Under Sink Quick Change Water Filtration System
$4 x 6.8 x 14"6.26 pounds2000 gallons or 6 months1.5 GPM25-125 PSI.
CuZn UC-200 Under Counter Water Filter
$$$4.5 x 4.5 x 15"8 pounds50,000g or 5 years2 GPM130 PSI max.
Woder 10K-Gen3 Ultra High Capacity Direct Connect Water Filtration System
$$3 x 3 x 15"2.75 pounds3 years or 10 000 gallons2 GPM60 - 125 PSI
Culligan US-600A Undersink Drinking Water Filtration System
$4.8 x 4.8 x 12.8"1.74 pounds1 year or 1 000 gallons1 GPM60 PSI
Aquasana 3-Stage Under Sink Water Filter System with Brushed Nickel Faucet
$$$12 x 4.2 x 9"7 pounds6 months or 600 gallons0.5 GPM20 to 80 PSI
APEC WFS-1000 Super Capacity Premium Quality 3 Stage Under
$$$18 x 12 x 10"14 pounds12 monthsDesigned for up to 5gpm20 - 85 PSI
iSpring US31 3-Stage Under Sink High Capacity Tankless Drinking Water Filtration System
$$$16 x 6 x 16"13.45 pounds2.000g or 1 year1 GPM90 PSI max.
Ecosoft 3 Stage Under Sink Water Filtration System
$$$16.5 x 6 x 14.6"8.4 pounds6 months0.25 GPM87 PSI Max.
Culligan US-EZ-4 EZ-Change Undersink Drinking Water Filtration System
$$3.8 x 9 x 14"4.1 pounds6 Months or 500 gallons0.5 GPM60 PSI
3M Aqua-Pure Under Sink Water Filtration System
$$$$22.5 x 4.9 x 4.7"4.75 pounds6000 gallons2.5 GPMup to 125 PSI

Wrapping Up

Well, there you have it. That was our extensive guide to getting the best under sink water filter out there. Hopefully, you have found our tips and expert under sink water filter reviews useful. Our main goal is to assist you in making the right decision.

Let us know if we did a good job and don’t forget to give us feedback regarding anything that might be left to be desired. We will take your advice to heart and will definitely try to satisfy your reading needs. Share our guide with others that might benefit from it and leave us a comment. Don’t forget to check out our other buying guides on water filtration as well. Thanks for reading and as always – stay put!

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