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Best water filter systems: improve your water's taste

(Image credit: WaterChef)

We spent 40 hours researching and evaluating water filter systems. We read manufacturer specifications, customer feedback and warranty fine print to learn how these systems work and what to look for in a good, reliable filter. Based on what we found, the Aquasana 3-Stage Under Counter water filtration system is the best one. This NSF-certified product removes 60 contaminants and is easy to install, compact in design and overall a decent value.

Best overall

Aquasana 3-Stage Under Counter

Removes 60 contaminants, including lead and rust
Difficult to reach live support

The Aquasana 3-Stage water filtration system fits under your sink and can remove 60 contaminants, including chlorine, asbestos, heavy metals like mercury and lead, and several organic chemicals. This water filter is certified by the NSF, which tested the system to ensure it really does remove the amount of contaminants it claims and improves your drinking water.

Along with the under-sink components, the Aquasana comes with a sink faucet, so you filter only the water you drink and not all the water flowing in your kitchen. This reduces how often you need to change out filters. An alarm sounds when it is time to replace the filters.

Installation is pretty straightforward. The filter comes with all the tubes and connectors you need. Once installed, the Aquasana is attractive and sleek.

The Aquasana comes with a 90-day guarantee and a one-year warranty. Our biggest complaint is it’s difficult to reach customer service representatives if you have a question or need a replacement part.

Best value

APEC Water ROES - 50

Replace filters every six to 12 months
Doesn’t alert you when filters need to be changed

The APEC Water ROES - 50 uses five stages to filter 40 contaminates from your drinking water. It works with all water types, including municipal, well water and very hard water. The contaminants it removes include fluoride, lead, copper and arsenic.

While most other systems need their filters replaced monthly, you only have to change the ones in this model every six to 12 months, which makes it an overall good value. However, it doesn’t alert you when you need to replace the filters, so you have to remember to check.

This water filtration system is designed to clean up to 50 gallons of water per day and can handle temperatures as hot as 120 degrees Fahrenheit. In addition, it filters waters with a pressure of 40 to 90 psi.

You install it under your sink, and it takes up quite a bit a room – it isn’t as compact as other models we evaluated. However, it is easy to install and comes with a standard sink faucet.

The APEC Water ROES - 50 has a standard one-year warranty.

Best warranty

WaterChef U900

Entire system covered by lifetime warranty
Doesn’t filter mercury or asbestos

The WaterChef U900 is a compact, under-sink water filtration system that is covered in its entirely by a lifetime warranty. Further, its filters have a long lifespan, only needing to be replaced once a year. This system is capable of removing 50 contaminants, including chlorine, led, pesticides and volatile organic compounds (VOC), but it doesn’t remove bacteria, mercury or asbestos. You can also use the WaterChef system to add compounds to your water, such as calcium and magnesium, which tend to enhance taste.

This water filter doesn’t use a multistage process to clean water as other systems do. Instead, it uses a single carbon block cartridge to remove contaminants in one swoop. The system notifies you when it is time to replace the cartridge.

The WaterChef U900 comes with a faucet you can install along with the full system. It also works with refrigerators to filter water for ice cubes and drinking. However, you need to purchase a separate fridge adapter.

Why trust us?

We’ve been evaluating water filtration systems since 2013 and have spent hours researching by comparing product pages, reading reviews and consulting with industry professionals. We learned that there are different types of filtration systems, including single-cartridge and three- and five-stage systems, each with its own pros and cons.

The National Sanitation Foundation (NSF) sets international standards for clean food and water, and we are familiar with its guidelines since several products we review, including water filters, are eligible for NSF certification. All the filters we reviewed are NSF-certified to meet strict health and safety standards. They are also compact enough to fit under your sink, and most of them are easy to install by yourself.

How we tested

We read customer feedback and installation guides to learn how to install water filter systems. By reading customer reviews, we learned which systems are easy to install and which come with everything you need to attach the components to your sink. Some models include extra connectors for sinks with non-traditional plumbing.

As we reviewed these systems, we considered the number of contaminants each one removes to be its most important feature. Most filter out about 40 compounds, including chlorine and lead. The best system, the Aquasana 3-Stage Under Sink, removes 60 contaminants. We found that some filters don’t remove contaminants such as mercury and asbestos, and we gave higher scores to systems that do remove these harmful elements.

We also considered each system’s overall value. To determine whether the water filter is a good value, we looked at its price, warranty length and filter lifespan. The industry-standard warranty is only a year, and we preferred systems with longer coverage. Also, we gave higher marks to systems whose filters don’t need to be changed monthly.

Water Filter Systems: what to look for

The best water filtration systems remove several contaminants, have a long life and don’t take up a significant amount of space under the sink. Furthermore, these systems offer a long warranty. Here are the criteria we used to evaluate these products:


Water filter systems tend to be relatively expensive. Some companies need to know more about your current set up before they can quote you a price for their product. We found that the least expensive water systems cost roughly $160 to $170. It isn't uncommon for some water filter systems to cost anywhere from $400 to $800. These more expensive systems should do a better job of removing contaminants from your drinking water and making it taste fresher. Some of these pricier units will let you know when the water filter needs to be changed, which can improve the life of your unit. Remember that you will need to replace your water filter every 6 months, which will also add to the cost of your water filter system.

Contaminants filtered

Most likely, the reason you desire a tap water filter is to remove any unhealthy contaminants and improve the water’s taste, smell or color. The best water filters will reduce 10 or more contaminants. Furthermore, look for water purifiers that have been NSF certified. The NSF Certification tells you the product meets strict health and safety guidelines and is routinely tested to ensure those standards are met. The best filter systems provide a performance sheet to show test results under the NSF standards. These sheets show the specific contaminants that are reduced and how much of each contaminant the filter removes.


Performance features

Under-the-counter water filters will reduce contaminants in different stages. It’s best to look for a filter that provides at least three separate stages to reduce pollutants from the water. Each stage will remove a different type of contaminant such as sediment, chemicals and residue. Furthermore, some filters can affect the pressure of the water. Systems that have a water pressure range of 55 to 65 psi are best since this is the ideal range for water pressure in your home. If you have a system with water pressure that is too strong, it can damage your pipes and cause leaks.

In addition, after a certain period of time, the filters on the system will need to be replaced. These can become costly if the faucet filters do not have a long lifespan. Six months is the average length of time most filters will last. A few filters, like the Kinetico AquaKinetic, have a lifespan of 12 months. The best systems have a notification system, whether by light or sound, that will alert you when it is time to replace a cartridge.


You do not want a water filter system that is large and bulky and takes up all the space under your counter. Before purchasing a system, ensure that it will fit under your sink. A water filter like the Pelican Pro 6 is especially compact and should fit in tight spaces. Additionally, most of these products do not require professionals to install them; you can hook them up on your own. We recommend looking for systems that include installation kits and filters that are easy to change. On many of the best water filtration systems, you can change a filter by simply twisting it on and off.

Help & support

Most water filters are covered under a one-year warranty. However, some manufacturers offer shorter time frames. Additionally, if questions or concerns do arise with your system, you want to ensure representatives are available, whether by email, telephone or live chat support.

Installing a water filter system is an easy way to keep you water safe as well as improve its taste, smell and color. A drinking water filter can be a little thing that has a lasting effect on your health.