Aquasana AQ-4000 (Recommended) Review of 2022 – WaterFiltersAdvisor

Water filters are essential in every home to maintain clean, pure water. One of our top picks is the Aquasana AQ-4000 Countertop Water Filter System. Here, we will review everything there is to know about this whole house water filter and why you should invest in one for your household.

Clary Technology

All Aquasana filters use NSF-Certified Claryum Technology in order to achieve ultimate purity, combining different methods of filtration and purification in a single cartridge. This technology removes up to 97% of contaminants from water and targets heavy metals such as mercury and chlorine. Plus, it even filters organic contaminants.

Eco Friendly

Aquasana is a top manufacturer of water filters nationwide. All of Aquasana’s products are eco-friendly, salt-free, and made from BPA-free plastic. Aquasana’s replaceable filters are specially designed to last up to six months at a time, which helps minimize waste.

Their eco-friendly promise does not stop with their products. At Aquasana, even their means of production hold true to their promise of eco-friendly solutions. Their primary manufacturing facility in Texas uses 100% wind energy.

Special Bundle Table

Aquasana Countertop Drinking Water Filter System -...
Aquasana Replacement Filter Cartridge for...
Aquasana AQ-4000W Countertop Drinking Water Filter System
Aquasana AQ-4035 Replacement Filter Cartridges
Best Feature/Benefit
The most economical way to get clean, crisp, safe water for your family
Retains the good minerals like calcium, potassium, and magnesium - the best drinking water for you and your family
Reduce 10x more contaminants than the leading gravity pitcher
Artichoke drinking water filters remove more contaminants at the best value
Star rating
Aquasana Countertop Drinking Water Filter System -...
Aquasana AQ-4000W Countertop Drinking Water Filter System
Best Feature/Benefit
The most economical way to get clean, crisp, safe water for your family
Reduce 10x more contaminants than the leading gravity pitcher
Star rating
Aquasana Replacement Filter Cartridge for...
Aquasana AQ-4035 Replacement Filter Cartridges
Best Feature/Benefit
Retains the good minerals like calcium, potassium, and magnesium - the best drinking water for you and your family
Artichoke drinking water filters remove more contaminants at the best value
Star rating

Main Features and Benefits

450 gallon Aquasana countertop water filter
Product Features Details
Capacity 450 gallons
Flow rate 0.5 GPM
Filter life 6 months
Main Advantage Reduce 10x more contaminants than the leading gravity pitcher
Installation Simple to install
Certification Full system NSF certified

This countertop water filter transforms your tap water into water that is pure enough to drink. Here are some of the main features and benefits of this water filter:

countertop water filter used in home AQ-4000
  • Removes over 97% of chlorine
  • No wastewater
  • No harmful contaminants added to your water
  • Keeps good materials during the filtration process


Filter Process

Clary Technology uses a combination of four filtration methods, including activated carbon, catalytic carbon, ion exchange, and absolute sub-micron mechanical filtration.

Filtration Performance

water filter process

As mentioned, the Aquasana AQ-4000 filter uses replaceable cartridges. These NSF-Certified cartridges can last up to six months before needing replacement to guarantee optimal filtration performance. Below we rate its performance by the type of contaminants each method targets.

Activated Carbon

Similar to refrigerator filters, Claryum Technology uses active carbon in the filter and replacements. This method is effective in reducing and filtering out pharmaceuticals, herbicides, pesticides, and volatile organic compounds (vows), in addition to any physical contaminants that may be in the water supply.

Catalytic Carbon

Catalytic carbon is a type of activated carbon that specifically targets the filtration of chlorine and chloramines. Most local water departments are required per EPA and NSF regulations to chlorinate residential water to prevent the growth of bacterias in the water supply. As a result, this can lead to differences in tastes and odor. The use of carbon fixes that problem and even promotes beneficial chemical reactions which further amplify the purification process.

Ion Exchange

Aquasana AQ-4000 systems use this filtration method to remove any heavy metals found in water, like lead and mercury. This additional step in the filtration process can even double as a water softener, removing harsh elements such as magnesium and calcium.

Absolute Sub-Micron Mechanical Filtration

The processes above are all conventional methods of water filtration. Aquasana takes it a step further by adding absolute filtration. This step targets contaminants such as asbestos and other chlorine-resistant contaminants. This works through the use of sub-micron mechanical filtration. The microns are much smaller than their target in order to capture even the smallest of contaminants such as bacterias and enzymes.

NSF Certification

Seventeen different Aquasana products are NSF certified, including the AQ-4000 countertop filter. Aquasana maintains consistent compliance with NSF standards. As a result, it has been able to maintain this certification for years.

NSF certified water filter

The company tests all its filters and provides a data sheet with test results. According to this sheet, the AQ-4000 has up to a 99% success rate in filtering out most contaminants. Here are a few of them:

  • Asbestos
  • Led Reduction pH 6.5
  • Cyst Live Cryptosporidium & Giardia
  • Turbidity
  • Benzene

Flow Rate

The flow rate can determine the effectiveness of a filter. We measure the flow by gallons per minute or gallons per hour.

This filter can supply filtered water on demand inside your home. You can also switch the water from filtered to unfiltered in a few seconds. Unfortunately, it does take time to fill because it does not have storage tanks. The rate of this filter is 0.5 gallons per minute equivalent to 30 gallons of purified water in an hour.

Step-By-Step Installation Guide

The Aquasana AQ-4000 countertop filter includes a user’s manual with steps for proper installation (see below). Overall, this filter and its replacement filter cartridges are easy to install. Both require little to no professional help or outside tools and materials.

easy to install countertop water filter

Step 1: Remove Aerator and Attach Diverter

First, remove your aerator and put on a brass adapter if needed. Make sure the rubber washer is in place.

Step 2: Hose Attachment

Next, connect the hose under the filter. Make sure it is in the proper place. Use the blue tip for the blue cap and the white tip for the white cap.

Step 3: Flush

After setting up the unit, open the diverter valve and flush for 10 minutes.

Warranty and Maintenance

90-Day Guarantee


Aquasana certified water filter

The Aquasana 90-day guarantee is as simple as it sounds. This warranty lets customers buy the product and try it out for 90 days.

Customers may return it for a full refund if they are not happy with the results. Keep in mind that you will have to cover your own shipping fees and any labor costs. Plus, installation fees are not covered in this warranty.

The company also offers a one-year limited warranty for defective products. Additionally, the company will send replacement parts. All you have to do is register your product and an agent will be with you to discuss the next steps.



easy to maintain in home

The AQ-4000 filter is simple to install and easy to maintain. Plus, the unit itself is made from BPA-free plastic meant to last.

The estimated life of the cartridge is six months. After this period, you have to buy a new one to replace it. If you are filtering out large amounts of water, you may need to change it more often. Just like the filter itself, the cartridges are easy to install.

In terms of day-to-day maintenance, it is important to keep in mind that this filter only works with cold water.

Pros and Cons

Just like any device, the Aquasana AQ-4000 has its own set of pros and cons. Here are a few of them to help you make your decision:

Easy installation
Easy maintenance
Reduce heavy metals in the water
Uses two filtration stages
NSF Certified
Only 11 cents per gallon
Eco-friendly; No harmful contaminants added
90-day money-back guarantee
Uses Claryum Technology
Will have to change out filters every 6 months or less
Only suitable for municipal water
Does not offer quality control options

Frequently Asked Questions

Below are answers to some of the most frequently asked questions to help assist you in product maintenance, purchasing, or any other concerns:

Does This Filter Purify Water?

Purified water is not always as good as filtered water. Purified water goes through processes that remove everything, including beneficial minerals. The Aquasana AQ-4000 countertop water filter removes any harmful contaminants and keeps the essential minerals. That is its guarantee of Ultimate Purity.

Do I Need a Plumber to Install It?

No. Installation takes three easy steps and should only take a few minutes.

Is the Filter Compatible with My Faucet?

The Aquasana AQ-4000 usually fits with standard U.S. and European faucets and comes with two adapters. Unscrew and check that there are screw threads inside the tap head. If it does not have an aerator that can be unscrewed, buy an adapter or use under sink systems to connect it.

Is This System Renter-Friendly?

This model is most suitable for renters since it does not require you to drill any holes or install additional water lines to your home. It sits on your counter ready for daily use.

Does This Filter Soften Water?

There are ways that the AQ-4000 can soften water because of its different filtration methods. Its use of water ionization minimizes and removes harsh metals and minerals. But it is not a water softener. Semi-softened water is just an extra benefit in terms of filtration performance. Aquasana has a different line of salt-free softeners.

How Do I Replace and Dispose of the Filters?

The replacement filters for this model are easy to set up and find online. Plus, they are biodegradable.

You can send your old filters to Aquasana and they will dispose of your filters for you. Additionally, you may throw them out with little environmental impact due to their composition.

Bottom Line

The Aquasana AQ-4000 Countertop filter is easily one of the best on the market due to its easy installation and maintenance, NSF certification, and eco-friendly composition.

To conclude, we at Water Filters Advisor highly recommend this water filter.

Aquasana takes the lead with NSF certifications. Along with that, Aquasana holds true to its eco-friendly promise in both its products and production. Above all, their customer service is impeccable. They are great at handling customer disputes, products, and warranties.

If the AQ-4000 is not for you, we guarantee that you will find the right one with Aquasana.