Aquasana AQ-4000 Review 2023: Is the Countertop Filter Good?

Came across the Aquasana countertop water filter but not sure whether is it a good buy?

Untreated tap water may contain harmful contaminants and chemicals like chlorine, chloramines, herbicides, pesticides, heavy metals, fluoride, VOCs, pharmaceuticals, and more.

These contaminants enter into the water supply system through various channels such as agricultural runoff, pollution, and wrong disposal of medicine which is unavoidable, and they couldn’t be removed by simply boiling the water.

Consuming these contaminants will bring adverse effects to your health in the long-term, so it is mandatory to filter your tap water before drinking.

When comes to the water filtration system, the countertop water filter is an excellent choice due to its fast setup, easy to use, and filtration performance.

In the US market, the Aquasana AQ-4000 is one of the most popular choices of countertop water filter, but the question is, does it perform as it expected to be?

In this Aquasana AQ-4000 review, I’ll equip you with all the important information and clear all your doubts so that you know exactly how it performs and most importantly, SHOULD you buy it?

Aquasana Countertop Water Filter AQ-4000 Review 2023

Aquasana AQ-4000 Review: Is the Countertop Filter Good? Image

Aquasana is one of the reputable market leaders when comes to manufacturing high-quality water filtration system, and one of their top sellers is the Aquasana AQ-4000 countertop water filter.

Aquasana AQ-4000 Review: Product Highlights

  • Remove or reduce more than 77 contaminants in water including sediments, chlorine, VOCs, PFOA & PFOS, pharmaceuticals, BPA, and atrazine
  • Last up to 6 months or 450 gallons of water
  • Quick and easy to install
  • 0.5 GPM water flow rate
  • Portable
  • Made in the USA
  • Tested and certified against NSF/ANSI Standards 42, 53, 401, and P473

Aquasana AQ-4000 Filtration Stages

The countertop water filter consists of 4 stages of filtration from 2 filter cartridges, which are:

Stage 1 – Activated Carbon: The most popular filtration media used to reduce chemicals like chlorine, herbicides, pesticides, and VOCs.

Stage 2 – Catalytic Carbon: To further remove chlorine and chloramine in tap water.

Stage 3 – Ion-Exchange: To remove heavy metals (eg: lead, mercury), and more charged contaminants.

Stage 4 – Sub-Micron Mechanical Filter: Remove asbestos, giardia, and cryptosporidium.

Aquasana AQ-4000 Review: Filtration Stages

The filtration process will remove the most harmful contaminants in the water while leaving the essential minerals beneficial to human health.

What Contaminants Do Aquasana AQ-4000 Remove?

According to the Performance Data Sheet, the Aquasana AQ-4000 Countertop water filter can remove or reduce at least 77 listed contaminants from water including chlorine, chloramines, heavy metals, VOCs, PFOA & PFOS, atrazine, and particulate.

Here are some of the tested data:

  • 99.9% reduction of live cysts such as Giardia and Cryptosporidium
  • 99.9% reduction of particulates
  • 97.4% reduction of Chlorine
  • 99.0% reduction in Turbidity
  • 99.3% reduction in Lead
  • 96.6% reduction in Mercury
  • 99.4% reduction in Volatile Organic Compounds (VOC)
  • 99.0% reduction in Asbestos
  • 81.8% reduction in Methyl Tertiary Butyl Ether (MTBE)

Aquasana Countertop AQ-4000 Review: The Pros

Being one of the popular countertop filters in the market, the Aquasana AQ-4000 Countertop Filter does come with several advantages.

1. Quick and Simple Installation

The AQ-4000 countertop filter is designed to be easily installed on the countertop to start providing clean drinking water to your family.

You don’t need to hire a plumber as you can set it up yourself in a few minutes, everything is self-explanatory.

Note: Not all faucets are compatible with the Aquasana AQ-4000, so make sure you check with customer service before order.

2. Great Filtration Performance

The AquasanaAQ-4000 countertop filter is capable to remove or reduce over 95% of most common contaminants found in tap water including chlorine taste and odor, VOCs, pesticides, herbicides, heavy metals (eg: lead, mercury), pharmaceuticals, giardia, and cryptosporidium.

The filtration performance has also been tested and certified by NSF International against NSF/ANSI Standard 42, 53, 401, and P473 which means what the manufacturer claims are trustable.

Most countertop water filters only get up to NSF Standard 401, but Aquasana AQ-4000 went further and certified for NSF Standard 473, which means it can remove PFOA & PFOS that could lead to diseases.

Some manufacturers may make a wild claim about their water filters in terms of filtration capabilities, but without certification from independent 3rd party organizations like NSF, those claims are still a question.

3. Good Water Flow Rate

The countertop system has a flow rate of 0.5 gallons per minute, which is good as you can fill up a standard 8 oz. glass in about 7 seconds.

4. Compact and Portable

The Aquasana Countertop AQ-4000 is compact and easy to install, which means you can bring it along while traveling and attach the diverter to the faucet to start enjoying clean and tasty drinking water.

5. Good Warranty Policy

The Aquasana AQ-4000 comes with a 90-day money-back guarantee for you to try it out worry-free as you can return it if you are not satisfied with the product.

After purchase, you will also be entitled to a 1-year warranty period for the product.

Aquasana AQ-4000 Review: The Cons

Nothing is perfect in real world, so as the Aquasana AQ-4000 countertop filter, and here are some of the disadvantages:

1. Moderate Capacity

The Aquasana Countertop AQ-4000 has a capacity of 450 gallons, which is considered small for large families with a high demand for drinking water.

2. High Maintenance Cost

The second drawback is the higher filter replacement costs due to the two high-performance filter cartridges. While you can get better-quality drinking water from it, however, it will cost you higher maintenance in return, especially if your family is big.

Tip: You may sign up for the Water for Life Program to reduce the filter replacement costs.

3. Limited Filtration Power

The third drawback is the limitation of filtration performance. While the Aquasana AQ-4000 performs pretty well in terms of contaminants removal as a countertop system, however, if you are looking for more filtration power, you’ll have to go for a multi-stages under-sink Reverse Osmosis system.

Aquasana AQ-4000 Review: Installation & Maintenance

The countertop system comes with brass adapters that fit 13/16” and 15/16” standard faucets, if you are unsure, the Aquasana customer support team is just one phone call away.

Below is the installation video in case you want to have a look before buying the system.

When to Replace the Filters?

The two filter cartridges can last about 6 months depending on water quality and usage.

Aquasana AQ-4000 Countertop Filter VS Water Filter Pitchers

In terms of performance, the Aquasana AQ-4000 filters more contaminants than water filter pitchers and the rate is faster too.

Besides, the capacity is larger, making it a less hassle and cost-effective option compared to the water filter pitchers.

Aquasana AQ-4000 Review: Should You Buy It?

By now you should know that drinking water right from the tap is not safe and could lead to adverse effects in the long-term, so getting a water filter is mandatory if you want to have a healthy body.

Aquasana is a reputable water filter manufacturer that you can trust in their products. Moreover, the Aquasana AQ-4000 is tested and certified by NSF for its performance in removing contaminants in water.

The Aquasana countertop water filter AQ-4000 is an ideal choice for those who want clean and tasty drinking water without much investment and hassle.

It is fast to set up, the price is fair, and most importantly, it does a great job in making sure your water is clean and safe for drinking.


The Aquasana AQ-4000 is ideal for small and medium families who are looking for a high-performance countertop water filter and willing to pay more in annual maintenance for higher-quality drinking water.

If that sounds like you, buy it now at the Aquasana website!

Got any questions regarding this Aquasana Countertop AQ-4000 review?

Let me know and I’ll get back to you shortly.


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