Under Counter Water Filter
3-stage Max Flow

The best performing water filter now with 44% faster water flow, 800 gallons of filter life capacity and Bluetooth® connectivity for filter tracking.

Select a faucet finish: Oil Rubbed Bronze
  • all-metal brushed nickel faucet
  • all-metal chrome faucet
  • oil rubbed bronze faucet
3-Stage Under Counter Water Filter Max Flow - Oil Rubbed Bronze is rated 4.4 out of 5 by 127.
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50% OFF 3-STAGE MAX FLOW SYSTEMS - limited time!
  • MSRP: 349.98
  • Sale: 174.99

Save 50% + free shipping with Water for Life $174.99

Questions? We can help

  • 866-662-6885
  • SAT: 9AM–5PM CST

Whole Health

Ultimate Purity*

Instantly transform ordinary tap water into clean, extraordinary water.

NSF Certified Claryum® filtration technology independently tested and proven to remove over 97% of chlorine and chloramines. Also reduces:

  • Heavy metals like lead and mercury
  • Chlorine resistant cysts like giardia and cryptosporidium
  • Organic chemicals like herbicides, pesticides and VOCs
  • Pharmaceuticals like estrone and ibuprofen

For a complete list of contaminants reduced please see our Performance Data Sheet.

Aquasana filters 10 times more contaminants

Whole Health

Ultra Delicious

Claryum®'s selective filtration technology retains naturally occurring beneficial minerals in your water like Calcium, Potassium and Magnesium for healthier, more delicious water!

Whole Health

Eco Friendly

Designed with the environment in mind! Intelligent system design reduces plastic waste by minimizing disposable plastic parts.

Pure Performance

Claryum® Technology

Activated Carbon Reduces pharmaceuticals, herbicides, pesticides, VOCs and MTBE.

Catalytic Carbon Targets chlorine and chloramines.

Ion-Exchange Filters heavy metals like lead and mercury.

Absolute Sub-Micron Mechanical Filtration Captures asbestos and chlorine resistant cysts like cryptosporidium and giardia.

The result: 10x more contaminants reduced than the leading pitcher plus healthy minerals retained for purely delicious filtered water.

Pure Performance

Easiest filter Replacement

Replacements engineered for ease. No need to disconnect hoses or water lines. Eco-friendly filter housing easily twists off so replacing your filters is a snap!

Pure Performance

Convenience & Value

Fewer filter replacements. More clean, great-tasting water.

One set of Aquasana Claryum® filters gives you 20x the capacity of the leading gravity-based pitcher at only 8¢ per gallon with Water for Life.

Pure Performance

Increase Performance

Extend the life of your system. Improve effectiveness.

Three Stage System features a 20 micron pre-filter to capture rust, sediment and silt that can clog your system. Extends filter life capacity to 800 gallons!

Pure Performance

A Smarter System

The Aquasana AQ-5300+ alerts you when it's time to change your filters. No more guessing if and when you need to replace your old filters.

Pure Performance

Designer Faucet

Match your kitchen décor with a designer faucet featuring all metal construction.

Pure Performance

Now connected with Bluetooth®

  • Track Gallons Filtered
  • Measure Environmental Impact
  • Estimate Dollars Saved by not buying bottled water
  • Alerts You When your filter is low
  • Order Replacement FIlters
  • Apple App Store for iOS
  • Bluetooth device

How It Works

Superior Filtration

Selective Claryum® Filtration

Reduces 77 contaminants while retaining beneficial minerals for optimal hydration.

Easy to install, replace & maintain

Filter lasts up to 6 months and features easy twist-off design.

certified by NSF

NSF Certified

Full system tested and certified to NSF/ANSI Standards 42, 53, 401 + P473 for the claims specified on the Performance Data Sheet.

  • 800 gallons
  • 6 month filter life
  • 1 year warranty
  • 90 day guarantee

Help & Support

Video Help

  • How to install the 3-stage Max Flow water filter
  • How to replace the AQ-5300+-R under counter filters

Installing the Max Flow under counter system

Replacing the 3 filters in the AQ-5300+

Learn More

Read the Reviews

Rated 5 out of 5 by from Love it I like the water flow and easy to change the filter and it lets you know when to change them.
Date published: 2018-11-23
Rated 5 out of 5 by from Installation and performance The installation was really straight forward and step by step. I was really impressed by the quality of the filter housing and faucet. Better than I expected. The performance is terrific and it has really a good quiet flow. I like that you can turn it on without having to depress a valve. Well done!
Date published: 2018-11-11
Rated 5 out of 5 by from So Far So Good First of all we're happy to get rid of the water cooler and the 5 gallon bottles! We live in San Diego and filtered water is a must. The water is tasteless, perfect, and the flow from the faucet is good. It was a relatively easy install for my husband.
Date published: 2018-10-13
Rated 5 out of 5 by from A Godsend We love it! Installation was easy and customer service was awesome
Date published: 2018-10-06
Rated 5 out of 5 by from Great Filer System This is a really great water filtration system. It was really easy to install with just basic tools. I would recommend it to anyone.
Date published: 2018-10-01
Rated 5 out of 5 by from AquaSana vs Clear2O pitcher, a big improvement We started filtering our water after an incident with the town water system a few years ago when VOCs were out of control. (The water company actually issued bottled water to the town's 25,000 residents.) That is when we started using a Clear2O pitcher solid carbon filter but hooking up to the faucet was a pain. Just recently we decided to replace our kitchen faucet, partly because repeatedly hooking up the Clear2O pitcher was damaging the faucet itself. Since we were eliminating the separate sprayer with the new faucet we decided to use the hole for a separate filtered faucet. I evaluated 6 water purification systems before choosing AquaSana. The installation was easy and, since I was replacing the kitchen faucet, the connection for the AquaSana filter was just one more step. I saw some other reviews that included a comment about the hoses popping loose. The installation instructions include a step to measure the insertion depth for the two hoses on the filter base which should eliminate any issues. Mine does not leak and the hoses have not popped off. The biggest problem was finding a place to mount the filter base without intruding in the under sink space and still leave enough room the change the filters. The water quality, taste and appearance equals or exceeds the Clear2O filter and the convenience is 10 times easier. I'm actually filling the now defunct Clear2O pitcher from the filtered faucet and storing in the refrigerator. I just sold my (small) inventory of Clear2O filters on eBay.
Date published: 2018-05-17
Rated 5 out of 5 by from The Best Water Ever! This filter system works beyond my expectations. I have use faucet filters for years, and when I tasted the water from the Aquasana system, I couldn't believe the difference (and was mortified at what I must have been consuming in water with the faucet filters). Installation would have been much easier if we hadn't had the garbage disposal to work around (we weren't confident enough to drop it and try to reattach after the filter system installation), but installation was just as the video demonstrated - simple and quick. I'm an Aquasana fan for life!
Date published: 2018-05-14
Rated 5 out of 5 by from Excellent filter that does what it claims to do. Installed very well - all sink installations differ and this filter seemed to accommodate the closeness of our sink.
Date published: 2018-05-09
Rated 5 out of 5 by from Water system We are very pleased with this system,will like the idea of receiving filers when they are due to be changed,was easy to install,would recommend this system.
Date published: 2018-05-01
Rated 5 out of 5 by from so far so good! The installation process and video were excellent. MY installation was more complicated because of the sunken sink so I needed to hire a professional to assist. However, this was a personal issue as I'm 73 and could not do under sink connection to the dispenser unit. Otherwise everything was simple.
Date published: 2018-04-25
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Learn More

Aquasana FAQs

  1. Do I have to pay for a plumber to install the system?

    Our under counter drinking water filter systems are very easy to install, and it only takes a few minutes to do; no plumber is necessary. If you have any questions or need assistance, our technical support representatives at 866-662-6885 can walk you through the installation process.

  2. How often do I have to replace the cartridges and how much do they cost?

    We recommend replacing the cartridges after six months or the specified gallon capacity to prevent the growth of bacteria in the system. The AQ-5100 Single Stage has a capacity of 200 gallons, the AQ-5200 Two-Stage has a capacity of 500 gallons, the AQ-5300 Three-Stage has a capacity of 600 gallons and the AQ-5300+ Three-Stage has a capacity of 800 gallons. Replacement filters cost $29.99 for the AQ-5100, $59.99 for the AQ-5200, $64.99 for the AQ-5300 or $79.99 for the AQ-5300+, but you can save 15%, get free shipping, and extend your product warranty by signing up for our no-contract auto-ship filter replacement program, Water for Life. The performance indicating device on the AQ-5200, AQ-5300 and AQ-5300+ systems will sound a beeping alarm and flash red when it is time to change your cartridges. The AQ-5300+ also contains Bluetooth connectivity so you can download our iPhone App and get alerts for when it is time to change your cartridges and even order new replacements straight from the App!

  3. Is this purified water?

    No, and actually, purified water is not as healthy as filtered water. Purified water undergoes reverse osmosis or distillation, which strip everything out of your water - not only the contaminants, but also the healthy, natural minerals. Our system uses selective filtration designed to reduce contaminants from the water and leave in the natural healthy minerals like calcium, potassium, and magnesium.

  4. How do I recycle the replacement filters?

    We have designed this system to minimize the environmental impact of our replacement elements, which are over 95% biodegradable carbon. Our company will recycle the filters for you, but we do not cover the shipping cost to return the filters back to us. In reality, the environmental impact of shipping the filters back to us outweighs the good of recycling. To recycle the drinking filters yourself, remove the ends of the filters, recycle the plastic parts (which are appropriately numbered) and put the carbon either in your compost pile or garden (carbon is good for plant life), or just throw it out (since the carbon degrades quickly, and is a positive component in a landfill).

  5. I'm a renter, so I can't drill or modify the plumbing. What should I do?

    To install an under counter system, you can remove the existing sprayer or soap dispenser on your sink and install our faucet in its place. This option will not damage or permanently modify your plumbing. When you move out, you can easily remove the system and reconnect your plumbing back to normal. If you do not have an existing hole in your sink from a sprayer or soap dispenser, we also have a countertop drinking water filter that conveniently screws on to most kitchen faucets.

  6. What is the size of the brass T-fitting for under counter and premium under counter unit?

    The most common size is 3/8" which originally comes with the system purchase. In rare cases some customers may need a 1/2" T-fitting which is sold separately and is available for purchase through technical support.

  7. What size hole do I need in my sink for the under counter and premium under counter systems?

    The faucet that is included with our systems requires a 1/2" hole.

  8. What does TDS mean?

    TDS is the acronym for Total Dissolved Solids, the amount of dissolved minerals and metals present in water. TDS meters tell you the concentration of dissolved minerals and metals, but are not an accurate measurement for contamination. Aquasana products reduce and remove harmful TDS like lead, but selectively retain or replace healthy dissolved solids like calcium, magnesium, and potassium.

  9. What is BPA? And why are people concerned about it?

    BPA stands for Bisphenol-A, a contaminant found in most plastics. BPA can adversely affect your health if consumed at high levels. Aquasana drinking systems do not contain BPA, and our filtration process reduces existing BPA.

  10. Does having hard water mean it is contaminated?

    Hard water is more of a nuisance than a health risk, and is not necessarily contaminated. Most water sources in the USA are considered hard. Hard water is generally safe to drink, after it has been properly treated.

  11. What is soft water, and is it safe to drink?

    Having soft water just means you have a lower concentration of dissolved minerals in the water (primarily calcium and magnesium). Soft water does not mean clean water. Your water can be soft and still contain contaminants.

  12. What is selective filtration, and how do Aquasana systems filter drinking water?

    Selective filtration is the process of sub-micron filtration, micron filtration, adsorption and ion exchange, all of which selectively reduces chemicals, heavy particulates and most dangerous heavy metals from the water while maintaining healthy minerals like calcium, magnesium and potassium.

  13. What is the difference between the single-stage, 2-stage and 3-stage under counter systems?

    All of our drinking water systems use the same Aquasana Claryum® filtration technology. The single-stage system lasts 6 months or 200 gallons before the cartridges need to be replaced. Our 2- Stage system has a higher capacity than the single-stage, giving you 6 months or 500 gallons of clean, filtered water. The 3-Stage system includes a 20 micron pre-filter before the two Aquasana Claryum® filters. This pre-filter increases the capacity of the system from 500 gallons to 600 gallons. In addition, it improves flow rate in high sediment areas. The 3-Stage Max Flow system adds even more capacity to 800 gallons, a 44% increase in flow rate at .72 gallons per minute and Bluetooth connectivity for filter tracking.

  14. I have an existing side faucet from a previous system. Can I use that with my new Aquasana water filter?

    We recommend that you use the faucet provided. We have extensively tested the system with the faucets included. The faucets are NSF Certified to have no lead content. In addition, they will not impart any unwanted chemicals into your water. If you choose to use another faucet, we recommend that you have a plumber install the system to ensure no leakage occurs. We also recommend that you install an NSF Certified faucet to ensure the health benefits of your new Aquasana water filter.

Learn More

User Q & A

My Aquasana faucett has developed a slow drip after about a year of use. Can the valve be replaced?

Asked by: RPDJR
they have parts online, but id bet aquasana would give you a new one. they are pretty good like that. they want life long customers 
Answered by: boy named soo
Date published: 2018-11-26

Are there filter elements included with the purchase of the system?

Asked by: Potable water
Yes. I also signed up for water for life and have filters automatically sent 
Answered by: Monk
Date published: 2018-11-24

What if I don’t want the faucet with it? I’ve installed these systems for customers. I already have a hot cold faucet for an instant hot. I just want this complete kit with everything to install, except no faucet. Is it possible? and price?

Asked by: Joel C
All Aquasana's Under Counter systems include a faucet. Because our NSF Certification requires every part of our system to be tested and certified, we can only guarantee our Certification with our components. However, you are welcome to use any cold water faucet you choose, it will not affect the price of the system.
Answered by: Aquasana Service Team
Date published: 2018-11-15

What is the length of the threaded-part of the faucet that goes under the counter. The granite top and the wood-board below take up almost 3" of thread. I would prefer at least a 1" thread for tightening the faucet. Total 4" I'm looking for.

Asked by: Jawahar.S
Jawahar, Thank you for contacting us! The threaded part of the faucet measures 3 1/2", unfortunately, we do not carry a faucet with 4" stem. If you choose to use another faucet, we recommend that you have a plumber install the system to ensure no leakage occurs. We also recommend that you install an NSF Certified faucet to ensure the health benefits of your new Aquasana water filter. Thank you, Aquasana
Answered by: Aquasana Service Team
Date published: 2018-11-06

What are the dimensions of the filtration unit? I need to ensure it will fit under my sink in my small apartment. Thanks

Asked by: Alanna
The 3-Stage Max Flow dimensions are: 12 7/8" H x 12" W x 4.25" D
Answered by: Aquasana Service Team
Date published: 2018-10-15

are your prices in USdollars or CDN.?

Asked by: alec
All prices are USD
Answered by: Aquasana Service Team
Date published: 2018-10-03

Does this system filter nitrates?

Asked by: E123456789
Nitrate/Nitrite removal requires special filtration through a membrane. Our Reverse Osmosis system is NSF certified to remove over 82% of nitrates/nitrites in your drinking water, as well as 87 other contaminants. For more information, please visit:  https://www.aquasana.com/drinking-water-filter-systems/reverse-osmosis-claryum
Answered by: Aquasana Service Team
Date published: 2018-10-03

What is the difference between the 3-stage water filter and the 3-stage max flow? Is there a difference in installation space needed?

Asked by: ting_squared
Please select the image below for comparison, or you may visit https://www.aquasana.com/drinking-water-filter-systems
Answered by: Aquasana Service Team
Date published: 2018-12-03
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Pure Performance

Now connected with Bluetooth®