Best Under Sink Water Filters (Top 5 Picks)

Under-sink water filters are an easy and effective way to improve the quality of your home’s water. By filtering out impurities like chlorine, lead, and sediment, these filters can give you and your family a continuous supply of clean, fresh-tasting water for drinking, cooking, and more.

Whether you are concerned about harmful chemicals, or simply want to improve the taste of your tap water, an under-sink water filter is a great investment.

In this article, I’ll take a look at the best under-sink water filtration systems. I’ll also discuss the different types of under-counter water filters and how they work.

Reasons to Buy an Under-Sink Water Filter

There are many reasons to buy an under-counter water filter, here are just a few:

  • If your family requires more than 2-3 gallons of filtered water per day, by installing an under-sink water filter, you’ll always have plenty on hand – and you won’t have to lug heavy bottles from the store anymore.
  • A water filtration system installed under your kitchen sink is a space-saving way to get clean, filtered water without taking up counter space.
  • Having an under-sink water filter gives you peace of mind knowing that you and your family are always drinking clean, fresh water.
  • Under-counter water filtration system can also save you money in the long run, as it will extend the life of your appliances and plumbing fixtures by preventing scale buildup.

Overall, an under-sink water filter is a great investment for anyone who wants to improve the quality of their home’s water supply.

Types of Under-Sink Water Filters

Here I’ll discuss the different types of under-sink water filters available on the market today. So, what’s the difference? And which type of filter is right for you?

Single-stage Under-Sink Water Filters

Single-stage filters are a great option for families who want the convenience of filtered water without the hassle of changing filter cartridges. Single-stage under-sink water filters use a carbon block filter to remove impurities from your water. This type of filter is very effective at removing contaminants like chlorine, lead, and bacteria from your water supply.

Multi-stage Under-Sink Water Filters

Multi-stage water filters are typically more expensive than their single-stage counterparts. But they offer a higher level of filtration, removing more impurities from your water.

If you’re concerned about the quality of your tap water, or you want the peace of mind that comes with knowing your water is as pure as possible, a multi-stage under-sink water filter is probably the way to go.

Reverse Osmosis Systems

Reverse osmosis is one of the most popular methods of water filtration. A reverse osmosis system consists of a membrane that filters out impurities and a storage tank for filtered water.

Reverse osmosis systems are available in a variety of sizes, from small under-sink units to large industrial systems. The size of the unit will determine the flow rate and the amount of water that can be stored in the tank.

Carbon Filters

Carbon filters are often used in under-sink water filtration systems because they are effective at removing a wide range of contaminants, including chlorine, lead, and sediment. They also do not remove beneficial minerals from water, like some other types of water filters do.

Under-sink carbon filters typically connect to the cold water line and have their own dedicated faucet. This allows you to easily switch between filtered and unfiltered water. Most under-sink carbon filters will need to be replaced every 6 months or so, depending on how much water you use.

Ultrafiltration

An ultrafiltration system is designed to remove contaminants from your water supply, such as bacteria and viruses. The system uses a hollow fiber membrane to filter out impurities, leaving you with clean, fresh-tasting water.

Installing an under-sink ultrafiltration system is a simple process and can be done in just a few minutes. Once the unit is installed, it will require very little maintenance, making it a convenient option for busy homeowners.

No matter which type of water filter you choose, be sure to get one that is certified by the National Sanitation Foundation (NSF).

5 Best Under-Sink Water Filters

#1. Best Overall: iSpring 6-Stage Reverse Osmosis System

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iSpring RCC7P-AK 6-Stage Reverse Osmosis System Under Sink with Alkaline Water Filter and Pump, pH+, 75 GPD, TDS Reduction, RO Drinking Water Filtration System
  • Reverse Osmosis requires high water pressure to force the impurities out of the water. RCC7P-AK’s extremely durable electric booster pump ensures high efficiency, reliable, and consistent performance regardless of pressure variations; delivering the highest performance for an RO system with less waste water.
  • High Capacity Reverse Osmosis water filtration for safer, healthier water. This under sink mounted water filter and water softener removes up to 99% of over 1, 000 contaminants, including lead (removes up to 98% of lead), chlorine, fluoride, arsenic, PFAS, asbestos, calcium, sodium, and more.
  • The RO membrane removes not only harmful pollutants but also a few helpful minerals. As a result, a standard 5 stage RO system produces slightly acidic water with a pH of 7. 0 or below. The iSpring RCC7P-AK includes an additional sixth stage - an Alkaline Remineralization filter which restores healthy minerals and produces a balanced alkalinity, which gives the water a more natural taste than regular 5 stage RO water.
  • With Premium quality components ensure highest reliability and low maintenance for many years to come. Clear see-through 1st stage housing makes filter inspection a snap. Pump power adapter: 100-240V 50/60Hz
  • For indoor use only. Extended Manufacturer upon registration, support from Atlanta GA USA
  • Filtration Type: Reverse osmosis
  • Capacity: 75 Gallons
  • Flow Rate: 1 GPM
  • Filtered Water to Waste Water Ratio: 1:1.5
  • Dimensions: 15″L x 8″W x 18″H

This incredible 6-stage RO filtration system is the best way to ensure that your family has access to pure, clean water.

Pros:

  • With a capacity of 75 gallons, this system will remove 1,000+ contaminants including lead, fluoride, chlorine, arsenic, and more. Providing peace of mind and great-tasting water for cooking, and drinking.
  • The electric pump included in the iSpring Reverse Osmosis System increases water pressure, making the system more powerful and efficient. This is a significant benefit, as reverse osmosis systems can sometimes have issues with water pressure. The pump ensures that your filter will work properly and efficiently.
  • The System comes complete with a brass faucet and filter cartridges with RO membrane, so you can install it and start using it right away. The sleek design of the brass faucet will add a touch of style to your kitchen sink.
  • The alkaline remineralization filter not only purifies your water but also adds back natural minerals that are beneficial to your health.
  • The filters need to be replaced every six months to a year, making it easy to maintain. The system has a low 1:1.5 ratio of filtered to wasted gallons.
  • This easy-to-install system will provide your family with filtered water for years to come.

Cons:

  • A bit pricey

#2. Best With Faucet Installation: Aquasana 2-Stage Under Sink Water Filter System

Aquasana 2-Stage Under Sink Water Filter System - Kitchen Counter Claryum Filtration - Filters 99% Of Chlorine - Oil-Rubbed Bronze Faucet - AQ-5200.62
  • Instantly Transform Ordinary Tap Water Into Clean Extraordinary Water - Reduces up to 99% of 78 contaminants including chlorine, lead, pesticides, PFOA/PFOS, microplastics, and more while leaving healthy minerals so you can drink with confidence. This system will NOT reduce Total Dissolved Solids (TDS)
  • High Flow Rate - This system powers through a half-gallon of water every minute. No need to wait for clean water compared to traditional drip filters.
  • Cost Efficient & Long Lasting - The most economical filter on the market at less than 10 cents per gallon filtered. Lasts for 6 months or 500 gallons before a replacement filter is needed.
  • Claryum Filtration - Removes impurities while selectively retaining healthy minerals, including calcium, potassium and magnesium for the healthiest drinking water.
  • Easiest Filter Replacement - Replacements are engineered for ease. No need to disconnect hoses or water lines. Eco-friendly housing easily twists off for snappy replacement.
  • Filtration Type: Carbon filtration
  • Capacity: 500 Gallons
  • Flow Rate: 0.5 GPM
  • Dimensions: 8.25″L x 4.25″W x 9″H

Pros:

  • This system removes 77 different contaminants from your water, including mercury, lead, chloramines, and chlorine. With three different faucet finishes to choose from, this under-counter water filter will match any kitchen decor.
  • It has a filtration capacity of 500 gallons of clean, filtered water before needing to be replaced.
  • The system uses carbon filtration to remove contaminants from your water, leaving you with clean, safe water.
  • This two-stage filter does not waste water because no RO membrane is used in the filtration process. The filter can last up to six months.

Cons:

  • The flow rate is not that impressive

#3. Best for Alkaline Water: APEC Water Systems ROES-PH75

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APEC Water Systems ROES-PH75 Essence Series Top Tier Alkaline Mineral pH+ 75 GPD 6-Stage Certified Ultra Safe Reverse Osmosis Drinking Water Filter System
  • Supreme quality – Designed, engineered and assembled in USA to guarantee water safety & your health.
  • This 75 GPD 6-stage system ROES-PH75 is guaranteed to remove up to 99% of impurities such as Chlorine, Taste, Odor, VOCs, as well as harmful Fluoride, Arsenic, Lead, Heavy Metals and 1000+ impurities. Max Total Dissolved Solids - 2000 ppm. Feed Water Pressure 40-85 psi
  • Premium made filter cartridge uses premium-grade calcium from trusted source for safe, proven water ph enhancement. Enjoy ultra-pure drinking water with added calcium minerals for improved alkalinity and great taste.
  • WQA certified system. Premium long lasting filters used to treat tap/well water. Provides unlimited clean drinking water.
  • America's no.1 rated water filter brand with 20 years of success guaranteeing trouble free, noise-free system for long lasting, dependable, pure drinking water.
  • Filtration Type: Reverse Osmosis, Alkaline
  • Capacity: 75 Gallons
  • Flow Rate: 75 GPD
  • Dimensions: 16″L x 5.25″W x 17.5″H

Enjoy the benefits of alkaline water with APEC under-sink water filter system. This six-stage filtration systemremoves sediment and carbon for a cleaner, healthier drinking experience. Alkaline water has many benefits, including improved hydration, better absorption of nutrients, and reduced acidity in the body.

Pros:

  • This top-of-the-line filtration system eliminates over 1,000 contaminants, including chlorine and heavy metals. You’ll love the difference in taste and quality of your water.
  • Superior Reverse osmosis technology that filters up to 50,000 gallons of water. Plus, it saves water by wasting significantly less during the filtering process than traditional systems.
  • The APEC under-sink water filter system is WQA certified, meaning that it has been tested and approved by the Water Quality Association. This certification gives you the peace of mind knowing that your water is safe to drink.
  • It comes with a lead-free designer faucet, making it a budget-friendly and chic addition to your home. The faucet is also easy to install, so you can enjoy filtered water in no time.
  • The two year extended warranty protects you in case of any problems with the system.

Cons:

  • It takes a bit more space than comparable systems

#4. Best Budget: Waterdrop 15UA Under Sink Water Filter System

Waterdrop 15UA Under Sink Water Filter System, Reduces Lead, Chlorine, Bad Taste & Odor, Under Counter Water Filter Direct Connect to Kitchen Faucet, NSF/ANSI 42 Certified, 16000 Gallons, USA Tech
  • Less than $31.99 per replacement filter (Search " B085G78F7R "on Amazon), save over 50% of cost on subsequent use.
  • 𝐔𝐥𝐭𝐫𝐚-𝐋𝐨𝐧𝐠 𝐒𝐞𝐫𝐯𝐢𝐜𝐞 𝐋𝐢𝐟𝐞:When used with municipal water, each under sink water filtration system has a maximum service life of 24 months or 16,000 gallons.[1]
  • 𝐈𝐧𝐧𝐨𝐯𝐚𝐭𝐢𝐯𝐞 𝐌𝐮𝐥𝐭𝐢𝐬𝐭𝐚𝐠𝐞 𝐅𝐢𝐥𝐭𝐫𝐚𝐭𝐢𝐨𝐧:The Waterdrop Direct Connect Under Sink Water Filtration System uses innovative multistage filtration. And it can effectively reduces PFAS, PFOA/PFOS, lead, chlorine, heavy metals, chemical iṁpurity, sediment and other large particles.[2] Enjoy healthy and pure water straight from your tap – no need to buy bottled water anymore!
  • 𝐒𝐨𝐥𝐯𝐞 𝐂𝐥𝐨𝐠𝐠𝐢𝐧𝐠 𝐏𝐫𝐨𝐛𝐥𝐞𝐦: By upgrading the filtration area, our filter now provides a 20X increase in dirt adhesion area, enhancing filtration capability while minimizing the risk of clogging.
  • 𝐈𝐀𝐏𝐌𝐎 𝐂𝐞𝐫𝐭𝐢𝐟𝐢𝐞𝐝 𝐅𝐢𝐥𝐭𝐞𝐫: Made from premium BPA-free and lead-free materials, the under sink water filter is certified by IAPMO against NSF/ANSI 372 Standard, ensuring reliable use from inside to outside. Certified by IAPMO against NSF/ANSI 42 Standard, the water filter can effectively reduce chlorine, taste and odor. Tested by third party laboratory against NSF/ANSI 53 standard it can reduce lead. To look over the 42&372 certification, please search "WD-15UA" on IAPMO official website.
  • Filtration Type: Carbon filtration
  • Capacity: 16,000 Gallons
  • Flow Rate: 0.75 GPM
  • Dimensions: 3.6″L x 3.6″W x 16.7″H

The Waterdrop under-sink water filter is the best budget option for those looking for a compact design that is easy to install. With push-to-connect fittings, it is a great choice for anyone on a tight budget.

Pros:

  • With the Waterdrop under-counter water filter, you can rest assured that lead, chlorine, heavy metals, and chemicals will be reduced for improved purity. Plus, sediment won’t stand a chance against this top-of-the-line filtration system.
  • With a service life of 24 months or 16,000 gallons, you can be confident that your family will have access to clean water for a long time.
  • Many water filters remove healthy minerals along with the bad stuff, but Waterdrop keeps healthy mineralslike calcium, magnesium, and potassium.
  • Whether you want clean drinking water at home, or on the go in your RV, this under-sink water filter can give you the peace of mind that your water is free of contaminants. Plus, installation is a breeze, so you can be up and running in no time.

Cons:

#5. Best Tankless: Waterdrop G3 Reverse Osmosis System

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Waterdrop G3 Reverse Osmosis System, 8 Stage Tankless Reverse Osmosis Water Filter, NSF/ANSI 42 & 58 & 372 Certified, Under Sink RO System, 2:1 Pure to Drain, Smart LED Faucet
  • 𝐓𝐫𝐮𝐬𝐭𝐞𝐝 𝐜𝐞𝐫𝐭𝐢𝐟𝐢𝐜𝐚𝐭𝐢𝐨𝐧𝐬: Waterdrop G3 reverse osmosis system is certified against NSF/ANSI 58 for TDS reduction and NSF/ANSI 372 certified for lead-free material. Also it has been tested and certified against NSF 42 to reduce chlorine, bad taste and odor. The tankless reverse osmosis system is also certified by the Federal Communications Commission. Besides, it meets the EU Standards and UKCA Standards for safety.
  • 𝟖-𝐬𝐭𝐚𝐠𝐞 𝐟𝐢𝐥𝐭𝐫𝐚𝐭𝐢𝐨𝐧: Tested by official third-party laboratory (SGS), the reverse osmosis system can effectively reduce TDS, chromium, PFAS, radium, fluoride, arsenic salt, iron, calcium, particles, chloride, chlorine and radioactive substances in your tap water. And our RO water filter system can reduce chemicals such as vinyl chloride, ethylhexyl acrylate, isobutylene, ethylene glycol, according to the reverse osmosis membrane technical manual.
  • 𝐒𝐦𝐚𝐫𝐭 𝐝𝐢𝐬𝐩𝐥𝐚𝐲 𝐟𝐚𝐮𝐜𝐞𝐭: The tankless reverse osmosis system is built with a smart display faucet. For instance, the TDS monitor tells you the quality of your filtered water, while the filter life tracker shows how soon you need to replace your filter.
  • 𝐇𝐢𝐠𝐡 𝐜𝐚𝐩𝐚𝐜𝐢𝐭𝐲, 𝟐:𝟏 𝐥𝐨𝐰 𝐝𝐫𝐚𝐢𝐧 𝐫𝐚𝐭𝐢𝐨: As an upgraded reverse osmosis system, this reverse osmosis water system produces 600 gallons of filtered water per day. By its low drain ratio, this system can produce only one cup of waste water for every two cups of pure water produced. Furthermore, with a fast and stable water flow rate, this RO system fills a 8 oz cup of water in 8 seconds, which is ideal for drinking and washing vegetables.
  • 𝐓𝐚𝐧𝐤𝐥𝐞𝐬𝐬 𝐝𝐞𝐬𝐢𝐠𝐧: Waterdrop G3 reverse osmosis system has a stylish look. This tankless design saves 70% under sink space. You can change a filter in 3 seconds without moving the system or using any tools. Note: This reverse osmosis system requires under-sink electricity.
  • Filtration Type: Reverse Osmosis, Carbon Block
  • Capacity: 400 Gallons
  • Flow Rate: 400 GPD
  • Filtered Water to Waste Water Ratio: 1:1
  • Dimensions: 18.12″L x 5.67″W x 17.72″H

This tankless reverse osmosis system provides an endless supply of clean water for your home or office. With a flow rate of 400 gallons per day, you’ll never have to worry about running out of clean drinking water again.

Pros:

  • The System uses a multi-stage filtration process to remove impurities from your water. A carbon block filter removes large particles, while an activated carbon block filters out smaller impurities. The RO membrane then removes even the smallest contaminants, leaving you with clean, fresh-tasting water
  • It comes with a water pump that provides increased water pressure while reducing water waste.
  • The system also comes with a built-in leak detector and faucet, so you can be sure that no water is wasted.
  • It features an indicator light that works as a reminder to replace the filter. This is a great feature because it ensures that you always have clean, filtered water.

Cons:

  • More expensive than other counterparts

Under Sink Water Filtration System – Buying Guide

Here’s a quick guide to help you choose the best under-sink water filter for your needs:

Unit Size and Kitchen Space

The first thing you need to do is measure the space under your sink. You will need to know the dimensions of the area so that you can purchase a filter that will fit properly.

Faucet Attachment

If your kitchen sink doesn’t have a pre-fabricated hole to attach the extra faucet that comes with most under-sink filters, then you’ll need to drill one. This can be a difficult and time-consuming task, so it’s important to consider all your options before buying an under-sink water filter.

A pre-drilled hole for your filter can make installation a breeze, and it’s worth considering if you want to avoid any potential headaches down the road.

Water Flow Rate

The flow rate is the measure of how much water can be filtered in a given period of time. For example, a filter with a flow rate of 0.5 gallons per minute can filter 30 gallons of water in one hour.

It is important to choose an under-sink water filter with a flow rate that meets your needs. If you have a large family, you will need a unit with a higher flow rate. Conversely, if you live alone or have a small family, you can save money by choosing a unit with a lower flow rate.

Installation

Under-sink water filters that use the main faucet as their water source are easy to install. The directions are typically easy to follow and the installation process is quick.

However, additional tubing and fittings are needed for the reverse osmosis filter which can add complexity to the installation. And if your under-sink cabinet space is limited, it may be difficult to find a place to put the extra equipment.

Under Counter Water Filters – FAQs

How do I choose an under-sink water filter?

There are a few things to consider when choosing an under-sink water filter:

  • First, you need to decide what type of contaminants you want to remove from your water.
  • Second, you need to consider the flow rate of the filter. The flow rate is the amount of water that can be filtered per minute.
  • Third, consider the size of the unit and the under-counter space you have.
  • Finally, you need to consider the price of the filter and the ease of installation of the replacement filters.

Which water filter removes the most contaminants?

Reverse osmosis (RO) process is the most effective way of removing a variety of different contaminants from water. And even better if RO is combined with the carbon water filtration process.

How often should I change my under-sink filter?

Under-sink water filters typically last for about 6 months before they need to be replaced. However, this can vary depending on the specific model and the level of water contamination. Some filters may need to be replaced more frequently, while others may last up to a year or more. It is important to consult your filter’s manufacturer for specific recommendations on replacement intervals.

How long do under-sink water filtration systems last?

Your under-sink water filter should last many years, as long as you remember to change the filter on a timely basis. If you forget to change the filter, there is a risk of contaminant buildup, which can reduce the lifespan of your under-counter water filter.

Do under-sink filters wastewater?

Conventional under-sink filters do not waste water, but reverse osmosis (RO) filters do.Reverse osmosis filters work by forcing water through a semipermeable membrane. The membrane only allows water molecules to pass through, not impurities. This process requires a lot of water pressure, and as a result, some water is lost in the filtration process.