Under Counter Water Filter
3-stage Max Flow

The best performing water filter now with 44% faster water flow and 800 gallons of filter life capacity.

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 4.3 out of 5 by 179.
  • y_2020, m_3, d_29, h_18
  • bvseo_bulk, prod_bvrr, vn_bulk_3.0.5
  • cp_1, bvpage1
  • co_hasreviews, tv_0, tr_179
  • loc_en_US, sid_226, prod, sort_[SortEntry(order=RATING, direction=DESCENDING), SortEntry(order=SUBMISSION_TIME, direction=DESCENDING)]
  • clientName_aquasanaserviceteam
  • bvseo_sdk, p_sdk, 3.2.0
  • CLOUD, getAggregateRating, 156.23ms
  • REVIEWS, PRODUCT
50% OFF 3-STAGE MAX FLOW SYSTEMS until Mar 31
  • MSRP: 349.98
  • Sale: 174.99

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

Questions? We can help

  • 866-662-6885
  • MON–FRI: 8AM–8PM CDT
  • SAT: 9AM–5PM CDT

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

Stylish
Designer Faucet

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

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 Working great I have had my water filter working for a month now. It's working great. Installation was very easy.
Date published: 2020-02-25
Rated 5 out of 5 by from Great filter! easy to install, clean fresh tasting non metallic tasting water with a sharp faucet!
Date published: 2020-02-23
Rated 5 out of 5 by from i am happy great tasting crystal clear water. i can fill a glass, put on top of my morning paper and can read through the water
Date published: 2020-02-01
Rated 5 out of 5 by from Easy install, smooth taste I finished the DIY setup in about 2 hours. Had to remove an old stubborn soap dispenser, so it took longer. I turned on the tap nervously, looked under the counter, and there were no leaks! That felt like enough to recommend the product right there. After letting it run for 20 minutes as directed, I tasted the water and it was smooth. There appeared to be little white specks floating around, but they disappeared after a few seconds and I realized they were just tiny bubbles. All in all, I'm happy with it. Even with the Max Flow model the flow rate is not that fast, but it's adequate. I have no clue whether our water is any "healthier", but it's giving me and my wife some peace of mind.
Date published: 2020-01-24
Rated 5 out of 5 by from Works great and easy to install System works great and was easy to follow instructions and install.
Date published: 2020-01-23
Rated 5 out of 5 by from Great Product and easy to install This product is awsome and very easy to install. The water is very clean, refreshing and tastes great. Filters lasted more than 8 months. The Andriod app helps a filter life remaining. Great product
Date published: 2019-12-24
Rated 5 out of 5 by from Owned 1 1/2 years. Works great, third filter replacement, no issues, no leaks. !00% satisfied.
Date published: 2019-11-28
Rated 5 out of 5 by from Quick and easy to hook up Installation went smooth and easy. The quality of the drinking water is good. So far so good, we are happy with this product.
Date published: 2019-11-16
Rated 5 out of 5 by from Great product, great tasting water When we did a kitchen remodel we wanted an undersink filter to replace the countertop pitchers we were using. After much research, we decided on Aquasana. The installation was easy, the water tastes great and the filters lasted six months. We get new filters with the Water for Life program and they are simple to replace. We use the water for drinking, cooking, the coffee maker and our cats’ drinking water. We love it!
Date published: 2019-10-19
Rated 5 out of 5 by from works great-no issues to date-upped water pressure Really enjoy water quality, peace of mind of pure water
Date published: 2019-10-04
  • y_2020, m_3, d_29, h_18
  • bvseo_bulk, prod_bvrr, vn_bulk_3.0.5
  • cp_1, bvpage1
  • co_hasreviews, tv_0, tr_179
  • loc_en_US, sid_226, prod, sort_[SortEntry(order=RATING, direction=DESCENDING), SortEntry(order=SUBMISSION_TIME, direction=DESCENDING)]
  • clientName_aquasanaserviceteam
  • bvseo_sdk, p_sdk, 3.2.0
  • CLOUD, getReviews, 6.04ms
  • REVIEWS, PRODUCT

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 (three months for the single-stage system) 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.

  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 for 800 gallons of filter life and a 44% increase in flow rate at .72 gallons per minute.

  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

What is the size (min/max) of the hole where the outlet is mounted?  I have a hole for a hand sprayer drilled through the granite counter. Rather than have another hole drilled, I want to disconnect the sprayer and use the same home for mounting spigot

Asked by: DanielW
I'm not at the house where the unit is installed but I can tell you what our experience was: We have a stainless steel sink with sprayer next to the faucet. We removed the sprayer attachment and installed the 3-stage unit (which was difficult due to the tight space under the sink, but finally did it). The hole left after removing the sprayer was too large for the filter faucet to sit tightly so we went to the hardware store and bought two stainless circular washers and two slightly smaller rubber washers. Putting one of each under the sink and one of each between the top of the sink and the filter faucet did the trick. Not as clean and gorgeous looking as it would have been without, but it's worth it to have the use of the filter. The filter unit is excellent, easy to change the filters, and I would recommend it to anyone.
Answered by: JulieA
Date published: 2020-03-28

can the under counter three stage water filter be attached directly to the sink faucet than on its on faucet?

Asked by: Ozzy
Hello Ozzy, 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. Thank you, Aquasana Support
Answered by: Aquasana S
Date published: 2020-03-05

Does the under sink purification system also reduce or eliminate arsenic?

Asked by: Potato
Hello, Fluoride or arsenic, both require Reverse Osmosis to be removed/reduced from water. We do offer a Point of Use Reverse Osmosis for your drinking water.   You may read more about our Reverse Osmosis system at: https://www.aquasana.com/drinking-water-filter-systems/reverse-osmosis-claryum If you are interested in a system, please call 866.662.6885 or e-mail sales@aquasana.com and a representative will be happy to discuss your needs and options.   Thank you,   Aquasana Support  
Answered by: Aquasana S
Date published: 2020-03-05

Do we have to use the faucets that come with this unit or will a different one purchased elsewhere work? I love your filtration systems but don't like the style of the faucets so would like something more modern. Please let me know. Thanks!

Asked by: NatalieF.
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. If you have any further questions please contact us at Support@aquasana.com Thank you, Aquasana Support
Answered by: Aquasana S
Date published: 2020-02-17

Had the filter for 3 months was working great. Now it stopped. No water comes out. Replaced the filters early and still no water. Any thoughts? 

Asked by: Thirsty mom
Hello, It appears you have several questions that would best be answered by a consultation with one of our experts over the phone. Please call our sales department at 866-662-6885, options 1 and 1 to discuss a potential solution for your home. Thank you, Aquasana Support
Answered by: Aquasana S
Date published: 2020-02-11

I’ve had the high flow 3 stage under sink filter for a while. I’ve changed the filters a few times. I just got new filters and installed them and the water flow is about half of what it was with the old set of filters. What would cause that to happen?

Asked by: Mich CT
Hello,   It appears you have several questions that would best be answered by a consultation with one of our experts over the phone.  Please call our sales department at 866-662-6885, options 1 and 1 to discuss a potential solution for your home.    Thank you,   Aquasana Support 
Answered by: Aquasana S
Date published: 2020-02-03

Hello, I am thinking of the 3-STAGE MAX FLOW I don't need the faucet, but I could run the filtered water straight to my fridge correct? I have an ice maker and water access there. Will this work? What price with, no faucet? Thanks, Randy

Asked by: The Nat One
Thank you for your email. Yes, you can have it going to the fridge directly or have it tee-d off, but we always advise that you might have a pressure drop. You can purchase a quick connect fitting from Home Depot or Lowe's, and connect the Tee-fitting to the outlet that goes into the faucet. Unfortunately we cannot make any other recommendations on what to use to connect it to the refrigerator being that our systems are not manufactured to connect with refrigerators/ice makers. Thank you, Aquasana Support
Answered by: Aquasana S
Date published: 2020-02-03

Is this product made in USA?

Asked by: MMavens
Note they say the filters are "assembled," not made in the US, but they don't disclose where they are made.
Answered by: XIMG
Date published: 2020-01-26
  • y_2020, m_3, d_29, h_18CST
  • bvseo_bulk, prod_bvqa, vn_bulk_3.0.5
  • cp_1, bvpage1
  • co_hasquestionsanswers, tq_245
  • loc_en_US, sid_226, prod, sort_[SortEntry(order=LAST_APPROVED_ANSWER_SUBMISSION_TIME, direction=DESCENDING)]
  • clientName_aquasanaserviceteam
  • bvseo_sdk, p_sdk, 3.2.0
  • CLOUD, getContent, 84.43ms
  • QUESTIONS, PRODUCT

To give you the best possible experience, our website uses cookies. You can review our privacy policy to find out more about the cookies we use and how to adjust your browser settings to block cookies. If you close this box or continue browsing our website, you accept our use of cookies.