How to choose Under sink water filter

The economical way to provide your family with a lot of filtered water safe for human consumption is by installing under sink water filter. The filtration method provides filtered water straight from the tap without taking up countertop space. There are different types of under sink water filters and each works differently. Here is a guide on how to choose under sink water filter that will suit you.

How to choose Under sink water filter

How to choose under sink water filter

There are a few features you should consider when buying an under sink water filter. These include:


There are two different types of under-sink water filter

  1. convectional/ under sink water filter with dedicated faucet
  2. simple/ direct inline.

Both types use cartridges combined with other technologies to provide filtered water, but installation is different.

Simple/ direct inline under sink water filter

As the name suggests the inline under-sink water filter is installed directly into the water line right underneath the kitchen or bathroom sink without drilling the countertop or having an extra faucet on the countertop.

Installation is simple no drilling or separate faucet is required.

It is mounted directly into the main water line under the sink in your kitchen.

All the cold water that gets in your kitchen sink’s main water line is diverted through the filter to be filtered.

The simple system is installed in an already existing faucet. No drilling/no separate faucet is required.

Advantages of direct inline

  • It doesn’t require a separate faucet for filtered water and unfiltered water.
  • This type is easy to install you do not drill a hole for an extra faucet.

Disadvantages of the direct line

  •  It is connected to the kitchen sink’s main cold water pipe/line so a lot of water is filtered you will have to change the filter more often therefore maintenance can be expensive.
  • If the water reaching the filter has high pressure it will overwork the filter and some water will pass through unfiltered.

Shop for the best inline under sink water filter

NameImagefilter lifeReplacement filterWhere to buy
1Woder under sink water filtration systemWoder-10K-DC Ultra High Capacity Under Sink Water Filter with Direct Connect Fittings10,000 gallons or 3-years.No replacement filter buy the system againAmazon
2CuZn UC-200 Under Counter Water FilterCuZn UC-200 Under Counter Water Filter50,000 gallons or 5 years.No replacement filter you replace the whole thingAmazon
3Watts Inline Water FilterWatts Inline Water Filter 20,000 gallonsAmazon
4Filtrete Advanced Undersink Water Filtration SystemFiltrete Advanced Under Sink Quick Change Water Filtration System 3US-PS012000 litersFiltrete Advanced Under Sink Quick Change Water Filtration FilterAmazon
53M Aqua-Pure AP2003M Aqua-Pure Under Sink Water Filter System AP2006 months3M Aqua-Pure Under Sink Replacement Water Filter Cartridge AP217Amazon
6Waterdrop 15UA Under Sink Water Filter Waterdrop 15UA Under Sink Water Filter System 16000 gallonsWaterdrop RF15 Replacement Filter Cartridge Amazon
Buy Waterdrop
7AQUACREST 5KDC AQUACREST 5KDC Under Sink Water Filtration System5,000 gallonsAQUA CREST GXRTDR Inline Water FilterAmazon
8GE GXK285JBL GE GXK285JBL Under Sink Filter System 300 gallonsGE FQK2J Under Sink Water Filter ReplacementAmazon
9APEC Water Systems CS-2500 APEC Water Systems CS-2500 Ultra High Capacity Undersink Water Filtration System 12 monthsAPEC FI-CS-2500 Replacement FilterAmazon
10PUREPLUS Under Sink Water FilterPUREPLUS Under Sink Water Filter22000 gallonsPUREPLUS WFC5300A Under Sink Water FilterAmazon
11Pure water Under Sink Water FilterPure water Under Sink Water Filter1500 gallons Pure water Inline Water Filter Amazon
12Wingsol Under Sink Water Filter  Wingsol Under Sink Water Filter8000 gallonsWINGSOL Under Sink Water Filter Replacement Amazon
13iSpring US21B Commercial Grade iSpring US21B Under Sink Water Filter System8000 gallonsiSpring FG15B-KS GAC and KDF Carbon Filter Replacement Cartridge
14Whirlpool WHAFFS Sink Water Filtration System Whirlpool WHAFFS Sink Water Filtration System 6 monthsWhirlpool WHAFFF Water Filter Amazon
15Frizzlife Under Sink Water Filter System  Frizzlife Under Sink Water Filter System12monthsFrizzlife FZ-2 Replacement Filter CartridgeAmazon
16Culligan US-600A Culligan US-600A Under- Sink Drinking Water Filtration System with Filter1000 gallonsCulligan D-20A Basic Drinking Water Filter Replacement CartridgeAmazon
17Hansing Under Sink Water FilterHansing Full Flow Under Sink Water Filter13000 gallonsHansing Under Sink Replacement Filter Cartridge for Model HSG-01Amazon
18Epic Smart Shield Under Sink Water Filter System Epic Smart Shield. Under Sink Water Filter, Inline 2464.3 Liters
Epic Smart Shield Replacement Filter
19InSinkErator F-1000S InSinkErator F-1000S6 monthsInSinkErator F-1000 Amazon

Under sink water filter with dedicated faucet

Under sink water filter with dedicated faucet is also known as conventional.

Its installation is complicated you require drilling and installing a separate faucet.

The system comes with a faucet that is installed on the countertop so requires drilling of the hole.

You need to divert the kitchen sink’s main cold water pipe/line to the filter using a connection.

When the water is filtered, it is sent to the separate faucet installed in the sink.

You will have two taps one for cold filtered water and the other one for cold unfiltered water.

This type will make your filter last longer because not all water that gets to your kitchen sink’s main cold water pipe/line is filtered.

In the conventional system, the pressure is reduced so all water that enters the system will get filtered.

Read the review for the best under sink water filter with a dedicated faucet


  1. You require a sink that has two faucet holes if not drill an extra hole in the sink
  2. It reduces the water flow rate 
  3. Requires plumbing for you to install the system.
  4. In the conventional system, the water pressure is low, therefore, you can wait for a few minutes before you get a full glass of filtered water.

Shop for the best conventional under sink water filter

NameImageContaminantsReplacement filterWhere to buy

bad odor, colors, chlorine, taste, particles, dust, and rust
Filter life: 1000 capacity
2Culligan US-EZCulligan - US-EZ-1 US 1 EZ-Change Under-Sink Drinking Water Filtration System with Dedicated Faucet and Filterparticulates class III, chloride and removes bad taste and odor
Filter life:3000 gallons
Culligan RC 1 EZ-Change Basic Water Filtration Replacement Cartridge Amazon
3AquasanaAquasana 3-Stage Under Sink Water Filter Systemlead, mercury, pesticides, pharmaceuticals, chlorine taste, odor, particulates, cryptosporidium, asbestos, herbicides, detergents, pharmaceuticals, and other volatile organic chemicals
Filter life: 800 gallons
Aquasana Replacement Filter Cartridges for 3-Stage Under Sink Water Filtration SystemAmazon
4Doulton W9330958 SuperCarb Under Sink Filter Systemq? encoding=UTF8&ASIN=B009EQNLMA&Format= SL110 &ID=AsinImage&MarketPlace=US&ServiceVersion=20070822&WS=1&tag=vibrantsuppliers 20&language=en US " >fine particulate matter, bacteria, cysts, turbidity,  pathogenic bacteria, hydrogen sulfide, lead,chlorine, taste, odor and organic compounds.Doulton W9120562 Sterasyl S Ceramic Filter CandleAmazon
5Whirlpool WHADUS5Whirlpool WHADUS5 Under Sink Water Filtration System with Chrome Faucetchlorine taste and odor, sediment, cysts, lead, and chemicals.
Filter life: 6 months
Whirlpool WHEEDF Dual Stage Replacement Pre/Post Water Filters Amazon
6Frizzlife under sink water filterFrizzlife Under Sink Water Filterlead, heavy metals, chlorine, chromium, mercury, rust, volatile organic compound, carcinogens, turbidity, odor and bad taste.Frizzlife FZ-2 Replacement Filter CartridgeAmazon
7Ecosoft 3 Stage Under Sink Water Purifier Filtration System  Ecosoft 3-Stage Under Sink High Capacity Tankless Drinking Water Filtration Systemchlorine taste and odor, salinity, lead, iron, manganese, tannins, dust, rust, and sediment Ecosoft 3-Stage Under Sink Water Filter Replacements Drinking Water CartridgeAmazon
8Brondell H2O+ Coral UC300 Brondell H2O+ Coral UC300 Three-Stage Undercounter Water Filtration Systemchlorine taste and odor, heavy metals (such as lead and mercury), industrial chemicals (like benzene), total dissolved solids, volatile organic chemicals Brondell H2O+ Coral Three-Stage Carbon Block Replacement Water FilterAmazon
9iSpring US31 3-Stage Under Sink iSpring US31 Classic 3-Stage Under Sink Water Filtration System dust, particles, dust, and dirt, cloudiness, chlorine taste, and odoriSpring F3 6-Month Prefilter Replacement Supply Filter Cartridge Amazon
10Watts Premier WP500313 2-Stage Undercounter Watts Premier WP500313 WP2-LCV 2-Stage Under-Countersimazine, atrazine, benzene, trihalomethanes (TTHM), lindane, xylenes, entamoeba cryptosporidium, giardia, chlorine taste, and odor Watts Premier WP560088 Two Stage Lead VOC Carbon Block Reduction Water Filter ReplacementAmazon
113M Aqua-Pure Under Sink Water Filtration System  3M Aqua-Pure Under Sink Water Filter System AP-DWS1000particulate, rust, lead, VOCs, MTBE, parasitic protozoan cysts, chlorine taste, and odor.3M Aqua-Pure Under Sink Replacement Water FilterAmazon
12Watts WP2BVC Premier Bacteria, Virus, & Cysts
chlorine taste and odor
13Watts Premier 500320 with UltravioletWatts Premier 500320 3-Stage Undercounter Drinking Water Filter with Ultraviolet lead, cysts, particulate matter, chlorine taste, and odorsAmazon
14New Wave Enviro-30008 New Wave Enviro 10 Stage Plus Water Filter Systemchlorine, trihalomethanes, organic and inorganic arsenic, mercury, lead, pesticides, and herbicides.New Wave Enviro 10 Stage Plus Water Filter Replacement CartridgeAmazon

Contaminants it removes

Under sink water filter has a combination of the filter with different technologies which each removes the specific contaminant such as

Bad Odor and taste

Since the system has a carbon-activated filter that helps remove chlorine odor and taste.
Also, an activated carbon filter removes organic, and inorganic chlorine, heavy metals, herbicides, pesticides, algae, and molds.

Removes heavy metal
The carbon filter combination removes heavy metals such as lead, mercury, chromium VI, and cadmium.

Particulate removal
The system has a polypropylene sediment filter that removes particles, dust, silt, and rust.

Reduce hard minerals (calcium and magnesium) that form scale on home appliances.

Not all systems are designed the same so make sure you purchase the system that filters contaminants present in your water.

You can use a water test kit to determine the contaminants present in the water.

Easy to install and maintain

Most of these systems are easy to install; they come with a DIY installation process that you can do alone at home without hiring a professional.

Since the system uses cartridges that require replacement after a period, the replacement should be smooth and straightforward.

Filtration Technology

Under sink water filter removes contaminants using different techniques such as

The reverse osmosis method uses a membrane. Contaminated water is forced to pass through the tiny pores of the membrane. The tiny pores only allow clean water to pass through and impurities are flushed into the drain. The method helps remove the total dissolved substance and heavy metals.

Find out the best systems that use the reverse osmosis method

Carbon filter

a carbon-activated filter that helps remove organic and inorganic chlorine, heavy metals, herbicides, pesticides, algae, molds, chlorine odor, and taste.

Ultrafiltration method

The ultrafiltration method uses a hollow fiber membrane to remove contaminants larger than 0.01 microns

Read a review for the Under sink ultrafiltration system

Under sink water System that uses ultrafiltration method

Alkaline under sink water filter

Some brands go up to six stages which include alkaline remineralization. The stage adds essential minerals such as calcium and magnesium, therefore making your water alkaline.

Read the review of the Alkaline under sink water filter

The system that alkalinizes the water

Wingsol Under Sink Water Filter  -8K gallons

Check the system that has the most filtration technology because it will help save a lot of money and space.

Furthermore, the more filtration stages there are, the better the system will provide quality filtered water.

Filter life

Under sink water filters use cartridges to filter contaminants in the water.

The cartridge doesn’t last forever so requires to be replaced.

You should know how long the filter will last for it to be replaced.

Some brands need their filter to be replaced after filtering specific gallons or a few months, but this can be different due to some factors such as the quality of water and amount of water filtered. 

You should follow the manufactures instruction on when to change the filter.

Some companies have a filter indicator to let them know when it needs to be replaced.

Water flow or pressure

As we said earlier if your water pressure is high and you are using a simple system some contaminants will escape and pass through unfiltered.

In the conventional system, the water pressure might be low, therefore, you can wait for a few minutes before you get a full glass of filtered water.

Know the flow rate of your system or water supply pressure before buying the filter.

Independent certification

Independent certification is the only way to guarantee your water system removes contaminants effectively and is made with quality material.

There are independent bodies such as NSF and WQA that test and approve most water systems.

Under sink water filter installation

I have prepared a list of websites to guide you step-by-step on how to install an under sink water filter.

This video might be a help too.

Under sink water filter is one of the best ways to make sure your family always has enough clean water for drinking regardless of the contaminant from the treatment plant or pipes.

We hope our guide on how to choose the best under sink water filter will help you find the right product for your home.

If there is a brand you want us to add to the list above, please let us know in the comment section below.

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