The Aquasana AQ-4000 is the LeafScore top pick for a countertop water filter. Here’s why.
Table of Contents
- Excellent for apartments and small spaces
- NSF certified
- Removes pesticides, VOCs, atrazine, and PFAS
- Outperforms Berkey by a mile
- One filter provides 11x capacity of leading gravity-based pitcher
- Very cost-effective
- Reduces or removes 77 listed contaminants
- Hose needs replacement after extensive use, becomes discolored
- Filter replacements are a bit finnicky until you get the hang of it
At a glance:
Made in: US
Certifications: NSF/ANSI Standard 42, NSF/ANSI Standard 53, NSF/ANSI Standard 401, NSF/ANSI Standard P473
Filters: Herbicides, pesticides, VOCs, atrazine, PFOA & PFAS, and more
Cost: $399
Filter replacement cost: $59.99 (or $50 with subscription)
What we like
The Aquasana AQ-4000 is the LeafScore top pick for a countertop water filter. It is:
- Easy to install and maintain
- Reasonably priced
- Certified to meet NSF standards 401, 42, and 53, as well as P473.
Those numbers mean that this unit not only reduces or removes all those things you’d expect, such as chlorine, it also reduces up to 15 separate new and emerging pollutants including pharmaceuticals, BPA, herbicides, and pesticides.
The filters in this unit provide more than two million square feet of filter material. This is impressive for a filter unit that only takes up a tiny amount of counter space.
How it performs
This twin cartridge system uses a combination of carbon filtration, ion exchange and sub-micron filtration. And, because the tap water is forced under pressure over filtration material it removes over three times more contaminants than leading pitcher filters.
The filtration system includes:
- Activated Carbon – to reduce pharmaceuticals, herbicides, pesticides, VOCs and MTBE.
- Catalytic Carbon – to reduce chlorine and chloramine.
- Ion-Exchange – to filter out heavy metals like lead and mercury.
- Absolute Sub-Micron Mechanical Filtration – to capture asbestos and chlorine resistant cysts like cryptosporidium and giardia.
The Aquasana water filtration system is designed to remove pollutants, reduce odor, and improve taste while preserving essential minerals such as magnesium, calcium, and potassium.
This unit has a flow rate of 0.4 GPM, meaning little noticeable difference between regular flow and filtered water.
See also: Why we ditched our Berkey in favor of an Aquasana
What does this filter remove?
The Aquasana Countertop system reduces or removes at least 77 listed contaminants. These include herbicides, pesticides and VOCs, atrazine, and PFOA & PFAS. It is certified to reduce chlorine by 97.4% and particulate by 99.9% and also boasts:
- 99.9% reduction of live cysts (Cryptosporidium and Giardia)
- 96.6% reduction in mercury
- 99.3% reduction in lead
- 81.8% reduction in Methyl Tertiary Butyl Ether (MTBE)
- 99.0% reduction in turbidity
- 99.4% reduction in Volatile Organic Compounds (VOC) by Surrogate
- 99.0% reduction in asbestos
Aquasana’s claims for this system have been tested and certified by NSF International against NSF/ANSI Standard 42 and 53.
Installation tips and tricks
To make installation a little easier, this unit comes with color coded hose ends and brass adapters that fit a variety of kitchen faucets. This includes adapters for 13/16” and 15/16” faucets which fit most kitchen faucets. If you have a specialty faucet, you may require additional adapters, and if your faucet is an all-in-one pull out sprayer, an under counter water filter may be the better option.
There are some quirks to this unit, though, such as learning the easiest way to replace the filters.
In our experience, it’s best to remove the blue filter first. This is fairly straightforward. The white filter, however, goes in the opposite way to the blue filter; nipple side facing the unit for the white filter, and flat side first for the blue.
To remove the white filter, it is easiest to use the fins at the end of the blue filter to twist the fins of the white filter (it will make sense once you see it!). You could also use pliers, but this risks damaging the filters or the unit.
The Aquasana AQ-400 functions optimally at a temperature range of 40-90 °F.
The Aquasana is one of the most economical and portable ways to get clean, great-tasting water. If you’re handy, you might want to take this unit on vacation to ensure clean water wherever you go.
No need to drill a hole in your sink or elsewhere, just attach the diverter to the existing tap.
Care and maintenance
To keep the Aquasana running optimally, it is a good idea to unclog the screens from time to time.
You can do this by unscrewing the part of the unit where the filtered water exits and removing the three small screens. Clean these using something like a silicon pastry brush or even a Q-tip.
We have found that the water flows faster once the screens are clear and you reassemble the unit.
Vs. Berkey and ZeroWater
The Aquasana AQ-4000 is easily the best countertop water filter around. It carries far more robust certifications than any other unit, largely because it relies on the pressure of tap water rather than gravity like the Berkey (View Price on Amazon) and ZeroWater models (View Price on Walmart).
The Aquasana isn’t particularly attractive, however, and does require hooking up to your faucet, meaning it isn’t immediately portable and can’t be used outdoors for picnics and parties. Still, the Aquasana is your best option if robust filtration is your priority.
In the section titled “What does this filter remove” the author fails to include important minerals the body needs like calcium and magnesium. So one must then supplement to get these minerals into the body. Hugely important oversight, made by many who are reviewing water filters.