The Aquasana AQ-4000 is certified to meet NSF standards 401, 42, and 53, as well as P473. This means that it not only reduces or removes all those things you’d expect, such as chlorine, it is also certified to reduce up to 15 separate new and emerging pollutants including pharmaceuticals, BPA, herbicides, and pesticides. That this unit does all that, is easy to install and maintain, and is reasonably priced means this is the LeafScore top pick for a countertop water filter.
Aquasana AQ-4000 Countertop Water Filter
Highlights: The Aquasana AQ-4000 is certified to meet NSF standards 401, 42, and 53, as well as P473. One Aquasana Claryum filter has 11 times the capacity of the leading gravity-based pitcher, making this a very cost-effective option. This system reduces or removes at least 77 listed contaminants, including herbicides, pesticides and VOCs, atrazine, and PFOA & PFOS
Aquasana AQ-4000 at a glance:
| Country of Origin: | USA |
| Certifications: | NSF/ANSI Standard 42, NSF/ANSI Standard 53, NSF/ANSI Standard 401, NSF/ANSI Standard P473 |
Our Review
- Excellent for apartments and small spaces
- NSF certified
- Removes pesticides, PFOA, and PFAS
- Outperforms Berkey by a mile
- Hose needs replacement after extensive use, becomes discolored
To make things easy, the 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, such as learning the easiest way to replace the filters. The blue filter should be removed first, and 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, then, 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.
To keep the unit running optimally, it is a good idea to unclog the screens from time to time. This can be done by unscrewing the part of the unit where the filtered water exits and removing the three small screens. You can then clean these using something like a silicon pastry brush or even a Q-tip. Water will flow faster once the screens are clear and you reassemble the unit.
The Aquasana AQ-400 functions optimally at a temperature range of 40-90 °F, and the filters in this unit provide more than two million square feet of filter material, while the unit only takes up a tiny amount of counter space.
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.
See also: The best home water filters for all types of use
One Aquasana Claryum filter has 11 times the capacity of the leading gravity-based pitcher, making this a very cost-effective option. And, because this system was designed with the environment in mind, plastic waste is reduced by minimizing disposable plastic parts.
See also: Why we ditched our Berkey in favor of an Aquasana
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 system reduces or removes at least 77 listed contaminants, including 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
The system has been tested and certified by NSF International against NSF/ANSI Standard 42 and 53 for these reduction claims and others. It was named one of Health Magazine’s Healthiest Gadgets for 2011 and remains one of the best countertop filters around.
The Aquasana has a flow rate of 0.4 GPM and is one of the most economical and portable ways to get clean, great-tasting water. If you’re handy, you might consider taking this unit with you 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.
Aquasana AQ-4000 vs. Berkey vs. 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.