Under Sink Water Filters

What is an under sink water filter?

An under-sink water filter is installed beneath your kitchen sink to deliver clean, filtered drinking water directly at the tap. Designed for point-of-use filtration, these systems provide consistent access to high-quality water without the need for refillable pitchers or countertop space. Filtration methods such as activated carbon, ultrafiltration (UF), or reverse osmosis (RO) reduce different contaminants while offering a convenient, discreet solution for everyday drinking and cooking water.

Where Under-Sink & Countertop Filters are Used

Under-sink and countertop water filters are versatile point-of-use solutions designed for residential, small commercial, and mobile applications where clean, filtered drinking water is needed. Their flexible installation makes them suitable for both permanent and temporary setups without complex plumbing. Common use places are the following:

• Refrigerators
• Water coolers
• Ice makers
• Kitchen counters
• Kitchen sinks
• RVs
• Boats

How to Understand Your Water Quality

Before you choose a drinking water filter, conduct a water test to learn about the quality of your water. Test results help match the right filtration system to your specific water quality concerns instead of guessing.

The water source plays an important role in treatment needs. Well water may require UV disinfection with sediment filtration to address bacteria, dirt, and debris. City water is already treated but often contains chlorine or chloramines, which activated carbon effectively reduces. If testing reveals high levels of microscopic contaminants or dissolved inorganic compounds, more advanced under-sink systems such as reverse osmosis (RO) or ultrafiltration (UF) may be the best solution for clean, reliable drinking water.

Why Choose an Under-Sink Water Filter

Under-sink water filters install out of sight beneath your counter, providing a space-saving and convenient way to get clean, filtered water straight from your tap. Many models include quick-change cartridges for easy maintenance, making them an efficient and low-fuss solution for everyday drinking and cooking water. Some systems may require a dedicated faucet, but all keep your countertop clutter-free. The benefits of under-sink water filters are the following:

• Convenient, on-demand access to clean water
• Space-saving, hidden installation under the sink
• Easy-to-replace quick-change filter cartridges

Types of Under-Sink Water Filters

There are several types of under-sink water filters, each using a different filtration method to improve the quality and safety of your drinking water.

• Activated carbon
• Reverse osmosis
• Ultrafiltration
• Ultraviolet disinfection

Use our buyer’s guide to find the best under-sink water filter for your refrigerator, RV, or well water.

Benefits of Under-Sink Water Filters

Different under-sink water filters require minimal maintenance and come with a range of perks such as:

• Convenient
• More extensive filtration options
• Standard carbon filters last 6 to 12 months
• Reverse osmosis membranes last 2 to 5 years
• Ultrafiltration lasts 1 to 2 years
• Ultraviolet disinfection lasts 6 to 12 months

Under-sink water filter with faucet included: NeoPure 4FC Compatible 0.5µ Carbon Filter

Under-sink water filter without a separate faucet: Neo-Pure TL1 Under-Sink Filter

Countertop Water Filters: An Alternative Option

Countertop water filters are a convenient, renter-friendly alternative to under-sink systems, offering effective filtration without permanent installation. These systems attach directly to your existing faucet and provide on-demand filtered water for home or office use, making them ideal when space or plumbing modifications are limited.
Why choose a countertop water filter:

• No permanent installation required ideal for renters and dorm students
• Easy faucet attachment with quick setup
• Delivers filtered water at up to 0.5 gallons per minute

Types of Countertop Water Filters

There are several different countertop water filters you can use in your home if you can’t install a large filtration system. These include:

• Carbon
• Ceramic
• Ultrafiltration

Benefits of a countertop water filter

• Easy to install and disassemble
• Doesn’t require permanent installation
• Extensive mechanical filtration options

Filtration Methods Explained

Ultraviolet Disinfection for Safe Drinking Water

Under-sink UV systems use ultraviolet light to disable bacteria and prevent the spread of infection, providing an added layer of protection even if municipal water is treated. Pairing UV with carbon or sediment filters ensures complete water treatment by removing debris, chemicals, and microorganisms. Some systems, like the Viqua VT1-VWS, combine both filtration and UV disinfection for maximum safety.
Under-sink UV systems protect water from:

• Cryptosporidium
• Giardia
• Dysentery bacilli
• Salmonella
• Mycobacterium tuberculosis
• Streptococcus
• E. coli
• Hepatitis B
• Cholera
• Algae
• Fungi
• Some viruses

Browse all UV water purifiers and learn more about UV water treatment.

Activated Carbon Filtration

Activated carbon water filters, available as under-sink units or countertop systems  are ideal for improving the taste and safety of city-treated water.  Carbon becomes activated when it is super-heated by steam. This process opens up more pores to maximize surface area for contaminant adsorption.  When KDF media is used with carbon, it enhances the life of the activated carbon by effectively reducing chlorine allowing the carbon to have more capacity to reduce other organic and chemical contaminants.

General activated carbon removes:

• Bad tastes and odors
• Chlorine and chloramines
• Trihalomethanes (THMs)
• Mercury
• Pesticides and herbicides
• Volatile organic compounds (VOCs)

 

Specialized carbon blends remove:

• KDF: Heavy metals, lime
• Antibacterial (Micro-Pure): Mold, algae, asbestos, bacteria
• Sub-micron carbon block: Lead, cysts

Browse all replacement carbon water filters and learn more about activated carbon.

Under-Sink Reverse Osmosis Systems

 Undersink RO systems have the broadest spectrum of contaminant removal.  They combine sediment and carbon filtration with a reverse osmosis membrane that removes 95-98% of total dissolved solids.

What do RO systems remove?

• Arsenic
• Fluoride
• Copper
• Lead
• Nitrate
• Cysts
• Total Dissolved Solids (TDS)

Browse all reverse osmosis systems and learn how reverse osmosis works.

Under-Sink Ultrafiltration Systems

Ultrafiltration also removes fine particulate like reverse osmosis, but it has a larger membrane pore size and does not remove dissolved minerals. Many people prefer under-sink UF systems because they receive fine filtration and the benefits of mineral water. Some ultrafiltration systems contain a .02 micron membrane that allows them to remove some viruses and parasites.

What do UF systems remove?

• Fine particulate
• Everything carbon and sediment filters remove
• Bacteria, viruses, and parasites through a .02-micron membrane

Browse all ultrafiltration systems and learn how the ultrafiltration membrane works.

Customer Reviews & Real World Use

Here’s what our guests had to say about their countertop and under-sink filters from Fresh Water Systems:

Everpure ADC RV filter

We will buy this product again.

We use it on our fifth wheel. We are very happy with the Everpure ADC RV Water Filter Cartridge because without the water we do drink has no taste. -- Yolaine

Everpure H-104 drinking water filter

Big bang for your buck.

The Everpure H-104 filter has almost all the features as the H-1200 system for a lot lower cost for filter replacement... I just installed the H-104 system in my daughters home. It sure beats bottled water and is bio-friendly to the environment. --Darryl D.

Browse residential drinking water filters by brand: Neo-Pure | Everpure | 3M

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