Water running through your pipes and faucets is essential for everyday life, but it can contain pollutants that affect taste or compromise safety. The best water filters remove harmful contaminants, allowing your family to enjoy clear, clean water from every spout.
Understanding Types Of Water Filters
Over 45% of the nation’s tap water contains chemicals, prompting a demand for residential filtration systems. Before selecting a unit, consider the various types of water filter systems available.
Multistage Filters
Remove contaminants and keep beneficial minerals with a sequence of filters. Water can pass through, but suspended solids, viruses, bacteria and macromolecules are trapped. The filters need to be periodically replaced, and little to no wastewater is produced.
Single-Stage Activated Carbon
A block of activated carbon absorbs chlorine, VOCs, pesticides and other chemicals as water flows through the filter. Its tiny pores can trap larger particles, making it more efficient than loose-packed filters. Carbon block filters need to be routinely replaced.
Reverse Osmosis
Water is pushed through a semipermeable membrane in the process of reverse osmosis (RO). Its pore size is smaller, allowing it to remove the highest volume of contaminants. However, this requires more energy and higher pressure. Along with filter cartridges, these systems need replacement RO membranes.
Ultrafiltration
This process is similar to RO but does not remove dissolved minerals, which can effectively preserve nutrients and taste. Ultrafiltration has slightly larger pores and uses lower pressure than RO systems.
Ultraviolet Sterilizers
Ultraviolet (UV) light can kill bacteria, viruses and microorganisms. The flow rate is controlled to ensure there is sufficient contact time between the UV light and the water passing through. UV sterilizers cannot filter out chemicals or physical contaminants.
Methodology For Filter Provider Selection
There are numerous undersink water filters on the market. These can be kept out of sight under your counter to save space and connect directly to a house’s cold water supply. Find the best water filter for you and your family by using these criteria:
- Filtration needs: Test your water and decide what to filter. You may be seeking something that reduces health problems identified by the EPA or one that tackles aesthetic impurities, such as poor taste or odor.
- Existing setup: Most water filters can be added to existing sink setups, requiring minimal installation. RO systems can be more complex. If you have limited space, then a compact unit may better suit your needs.
- Ratings and compliance: The National Sanitation Foundation sets standards for the performance and safety of water treatment products. Undersink filters list their NSF and similar certifications.
- Filter budget: Factor in the costs of the initial purchase, installation, maintenance and filter cartridge replacements. It is recommended to choose systems with long lifespans and affordable replacement parts.
- Brand transparency: A water filter cannot fully eliminate all possible contaminants, so be cautious of any providers that make such claims. Instead, seek a product that reduces the pollutants of most concern in your home.
Best Water Filters For Homeowners
Below are some of the top water filters and leading providers to consider.
1. Aquaperform – Multipure
Multipure offers some of the best water filters internationally. The Aquaperform combines performance and durability to remove contaminants from water, including arsenic V. It has NSF Standards 42, 53 and 401 certifications. The solid carbon block filter system can be installed under the sink or on the counter, and it comes with the hardware you need — no professional installation required.
There are other Multipure filters to choose from to meet different needs and budgets, including the Aquapremier with Nanomesh™ technology or the compact Aquamini. All filters and cartridges adhere to NSF certifications and rigorous quality assurance protocols.
Key features:
- Third-party tested and certified
- Authorized Multipure dealers globally
- Products built to last a lifetime
2. Under Sink Water Filter – Hydroviv
A PhD scientist developed Hydroviv filters to provide families with safer water. The company can create custom filtration solutions tailored to your needs. The Hydroviv Under Sink Water Filter has seven-stage filtration to reduce lead, arsenic, VOCs and more. For safety and performance, this system meets NSF/ANSI Standards 53, 42 and 372.
The Hydroviv Under Sink Water Filter easily connects to your cold water line, and each cartridge lasts about six months before needing to be replaced.
Key features:
- IAPMO-certified protection
- Science-backed filtration
- Quick installation
3. Under-Sink Reverse Osmosis System – Brita PRO®
Brita PRO uses RO to more thoroughly remove contaminants from your water supply. This robust system targets copper, lead, nitrate, fluoride ions, and other contaminants or pollutants. It is best installed by a professional. The brand is a highly trusted name for protecting residential water supplies.
RO is a slightly different process from standard water filtration and removes the widest range of impurities. Therefore, the Brita PRO system is a great choice for families in areas with well water or industrial pollution, or who simply want the highest purity available.
Key features:
- State-of-the-art technology
- Certified system of filtration products
- Reduces scale buildup
4. Coral Three-Stage Filter System – Brondell
Brondell is committed to providing clean water to its customers and to protecting the planet’s essential resources. The Coral Three-Stage Filter System is simple to install and can remove over 75 contaminants. For ease of use, it operates without the need for electricity or batteries.
It meets NSF/ANSI standards 42, 53 and 401, along with NSF/ANSI/CAN 372 and CSA B483.1. The company’s designs are patented and backed by third-party testing, ensuring customers receive a high-quality water filter.
Key features:
- Partnership with 1% for the Planet
- Long 12-month filter life
- Affordable pricing
5. US-3UF Ultra Filtration Under Sink Filtration System – Culligan
Culligan offers a premium three-stage filtration system. It reduces a range of contaminants, including bacteria, viruses, lead, microbial cysts and atrazine. The system can help improve the taste and scent of your drinking and cleaning water. Cartridges need to be replaced about every three months for the best results.
If you’re seeking a more basic and affordable unit, Culligan also offers the US-EZ-1 EZ-Change Under-Sink Drinking Water Filter System. It reduces poor tastes and odors, chlorine and particulate class III. Culligan filtration systems come with step-by-step installation instructions.
Key features:
- WQA testing and certification
- High-quality products with DIY installation
- Basic to premium filter cartridges available
6. Cloud RO – Cloud
Remove up to 99% of toxins with Cloud. The undersink RO system features an internal hydraulic pump that optimizes water pressure. Its remineralization filter adds calcium, magnesium and potassium into the water for improved taste and nutrients. Once water is filtered, it is stored in a 2.8-gallon tank.
Cloud is an excellent choice for filtration power and flow rate, with a low wastewater ratio. The NSF-certified filtration technology is easy to install but requires basic plumbing knowledge. Previous customers appreciate the easy installation, delicious-tasting water and overall convenience.
Key features:
- Track filter status with the Cloud app
- Alkaline water with healthy minerals
- Four faucet options available
7. ECO Pro – AQUAPHOR
AQUAPHOR’s ECO Pro features a two-in-one treatment cartridge for deep filtration and antibacterial protection. The unit occupies only a small amount of space beneath the sink, and cartridges can be replaced without the need for tools. AQUAPHOR offers two smaller undercounter water systems for your home – Crystal Solo and Crystal Solo B.
The hollow fiber membrane in the ECO Pro features fine pores that filter out microparticles, making the water safer for both adults and children to drink. All of the brand’s filters remove chlorine, heavy metals, pesticides and rust.
Key features:
- Antibacterial protection
- Extended filter life
- Retains essential minerals
8. SMART Classic Under Sink Water Filter System – Crystal Quest
Purify tap water with this BPA-free and ISO-certified system from Crystal Quest. Various filtration capacities and connection types are available, including an ice maker hookup or a leak-detecting valve. While the SMART Classic Under Sink Water Filter System is designed for effective filtration, it is not currently certified by NSF.
Crystal Quest products are manufactured in the U.S. and shipped worldwide. It has served over 1 million families and businesses.
Key features:
- Six filtration stages
- Optional additions and upgrades
- Highly rated by previous customers
9. U9000 Premium Under-Sink Water Filtration System With Intelligent Monitor – WaterChef
WaterChef provides cleaner and healthier water from your tap, meeting NSF/ANSI standards. The U9000 Premium Under-Sink Water Filtration System With Intelligent Monitor is made of robust stainless steel and comes in multiple finishes to match your kitchen.
While reducing contaminants, this system retains beneficial minerals for a naturally refreshing taste. The Intelligent Monitor™ tracks your water usage, and you can opt for an Auto-Ship subscription for cartridge replacements.
Key features:
- Durable performance with a lifetime warranty
- IAPMO Platinum Certified
- Low cost per gallon
10. RCC1UP 6-Stage 100 GPD Under Sink Reverse Osmosis Drinking Water Filtration System With Booster Pump and UV Ultraviolet Filter – iSpring Water Systems
This RO filtration system from iSpring Water Systems is highly efficient and easy to maintain. It can reduce up to 99% of contaminants in a water supply and filter up to 100 gallons daily. The 11W UV filter automatically powers on and off as water flows through to kill microorganisms. It is an especially great choice for well water supplies.
iSpring Water Systems values customer satisfaction, so the team can help you choose the right system for your needs and offers 24-hour delivery across the U.S.
Key features:
- Fine micron and layered defense
- Quiet operation
- Rigorous annual testing
Under-the-Sink Filter Comparison
Evaluate each company’s filter systems, including their certifications and key features.
| Provider | Featured Filter System | Installation | Certified by NSF | Approximate Filter Capacity or Lifespan |
| Multipure | Aquaperform | DIY-friendly for most users and all hardware included | Yes | 600 gallons |
| Hydroviv | Under Sink Water Filter | DIY tool-free installation | Yes | Six months |
| Brita PRO | Under-Sink Reverse Osmosis System | Professional installation recommended | Yes | Six to 12 months |
| Brondell | Coral Three-Stage Filter System | DIY with step-by-step guides available | Yes | 600 gallons or 12 months |
| Culligan | US-3UF Ultra Filtration Under Sink Filtration System | DIY with video guides available | Yes | 500 gallons or six months |
| Cloud | Cloud RO | DIY with basic plumbing skills or a local professional | Yes | Nine to 12 months |
| AQUAPHOR | ECO Pro | DIY with video instructions or professional installation available for a fee | Yes | 640 gallons or 12 months |
| Crystal Quest | SMART Classic Under Sink Water Filter System | DIY possible, plumber for code compliance if needed | No | Unspecified |
| WaterChef | U9000 Premium Under-Sink Water Filtration System With Intelligent Monitor | DIY and step-by-step video available | Yes | 12 months |
| iSpring Water Systems | RCC1UP 6-Stage 100 GPD Under Sink Reverse Osmosis Drinking Water Filtration System With Booster Pump and UV Ultraviolet Filter | DIY with basic plumbing skills or a local professional | Yes | Six to 12 months |
The Importance Of Water Filtering
Sink water is used for various tasks every day, from hydration and bathing to washing dishes and cooking. The water source, local geology and municipal treatment primarily influence the quality. Whether you have city or well water, it can contain harmful contaminants that can impact its aesthetics or safety.
Undersink water filters offer a solution by removing contaminants through a series of specialized filters. Depending on the type and its certifications, some are highly effective at reducing lead or removing 70% to 90% of microplastics from a water supply. Reliable systems can create safer, better-tasting drinking water and prevent mineral buildup in pipes and appliances.
When you get safe and tasty water straight from the faucet, you can save money on buying prefiltered plastic water bottles. Approximately 500 billion plastic bottles are used globally each year, yet only 12% are properly recycled. Reusable versions are far better for your wallet and the environment.
Keep Up With Filter Replacements
Water quality and usage will influence a filter’s lifespan. As undersink water filters work, they eventually become saturated with contaminants. This can reduce their effectiveness, lead to clogs or even introduce new bacteria.
Manufacturers provide guidelines for filter replacement, such as replacing filters in Multipure’s Aquaperform about every 600 gallons. Some systems feature LED lights that change color according to the filter status.
In addition to recommended guidelines, it is likely time to replace your undersink water filter if you notice a decline in water quality, a lower flow rate, or unusual smells or tastes. Additionally, the EPA recommends that homeowners test their water supply for microbiological contamination at least once a year and for chemical contamination every three years, especially if they have well water.
Healthy Hydration In Your Home
The water from your faucet may contain impurities that affect its quality, and purchasing plastic bottles is an ongoing expense. Undersink filters are a dependable, cost-effective solution. Once installed, all you need to do is remember to replace the filter cartridges in a timely manner. Get the peace of mind you deserve by installing one of the best water filters under your kitchen and bathroom sinks.
Author Bio
Jane is an environmental writer and the founder and editor-in-chief of Environment.co where she covers sustainability and eco-friendly living.
