Aquasana OptimH2O Drinking Water Filter System Review 2023

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In this review, you’ll learn about the advantages and drawbacks of the Aquasana OptimH2O reverse osmosis water filter. In a nutshell, the system features a 3-stage filtration process with an additional remineralization stage – adds bits of healthy minerals to your water – to provide crystal clean and great-tasting drinking water. 5 NSF certifications guarantee the effective removal of a broad range of contaminants making the Aquasana OptimH2O RO system perfect for people who don’t want to make compromises when it comes to drinking water quality. The price? It’s fair!

Aquasana OptimH2O

Aquasana OptimH2O

Price: $$
Filter Stages: 4
Purified Water: 32 Gallons Per Day
System Certifications: NSF 42, 53, 58, 401, P473
Annual Cost: $180-220

Our Rating

Aquasana OptimH2O Reverse Osmosis System – Key Features

Let’s start with the filtration process:

  • Filter stage 1: A basic activated carbon filter reduces chlorine and traps other, larger particles. As a result, your water will not only taste and smell much better, the reverse osmosis membrane at the heart of the system is also protected from aggressive substances
  • Stage 2: The reverse osmosis membrane reduces many potentially harmful contaminants such as nitrates & nitrites, lead, cysts, and pentavalent arsenic.
  • Filter stage 3: Claryum carbon which is a proprietary mixture of activated + catalytic carbon helps to eliminate 5 times more contaminants than the RO process would alone. This includes herbicides, pesticides, chloramines, a bunch of heavy metals, pharmaceuticals and more.
  • Remineralization stage: Finally, it’s time to get those healthy minerals that were lost during the filtration back into your water. Furthermore, the mix of calcium, magnesium, and potassium helps to balance pH (alkalinity) and create a natural taste. The remineralization stage is also why when testing the purified water it won’t read “0” TDS, which is not a water quality issue!

The full system is tested and certified to NSF/ANSI standards 42, 53, 58, and 401 and also conforms to NSF Protocol P473. Needless to say that if you are looking for a water filter to finally get rid of those nasty contaminants lurking in your water the Aquasana OptimH2O RO system is it!

Just for clarification:

  • NSF Standard 42 tests a water filter’s ability to remove chlorine/chloramine and other particulates from water that create unpleasant taste and odor.
  • Standard 53 tests for the reduction of contaminants with health effects.
  • Standard 401 is for emerging contaminants that have found their way into our water systems in recent years – think a bunch of herbicides, pesticides, certain pharmaceuticals, and detergents.
  • Standard 58 is specifically for point-of-use reverse osmosis systems. The standard covers Total Dissolved Solids (TDS) rejection and other optional contaminant reduction claims.
  • Protocol P473 is for PFOA and PFOS. The abbreviations stand for perfluorooctanesulfonamide and perfluorooctanesulfonic acids respectively. Both groups of substances are known carcinogens.

Feel free to open the following tab to check out some of the reduction rates the Aquasana OptimH2O could achieve in independent lab tests.

Contaminant Reduction Rates

Please note: This is only an excerpt!

NSF Standard 42

Chlorine: 97.66%
Chloramines: 97.66%

NSF Standard 53

Cysts: 99.99%
Mercury: >95.8%
Lead: >99.3%
VOCs: ~99.4%
Asbestos: >99.0%

NSF Standard 58

Arsenic(V): 97.6%
Chromium Hexavalent: 97.0%
Fluoride. 95.7%
Nitrate/Nitrite: 82.40%
Radium: 226/228 80.0%
TDS: 95%

Standard 401

Bisphenol A: 98.9%
Ibuprofen: 95.4%
TCPP: 97.8%

NSF Protocol P473

PFOA & PFOS: 96%

All in all, the system is guaranteed to remove up to 99% of 88 different contaminants. And as far as filtration capacity is concerned, real-life daily water production is 13.32 gallons. This may not be as much as you get with other reverse osmosis filter models, but for regular household use it’s more than enough.

And lastly, at .5 gallons per minute water flow the system wastes about 3 gallons of water for every gallon filtered. This sounds like a lot but it’s actually pretty average for RO systems that don’t utilize a pressure pump.

Recommended operating pressure: 40-100 psi.

Aquasana OptimH2O Pros

There’re a few additional features we’d like to mention.

First of all, system installation and maintenance are DIY-friendly. A user manual with detailed step-by-step instructions is part of the package, plus you can check out the helpful videos on YouTube.

Next, you can choose from 3 dedicated, full-metal faucet designs to match your kitchen decor: Chrome, brushed nickel, and oil-rubbed bronze.

And last but not least, Aquasana offers a 2-year limited warranty as well as a 90-day satisfaction guarantee on this product which got you covered in case something goes wrong.
Aquasana OptimH2O

The Aquasana OptimH2O – learn more on

System Installation

The full package includes the first set of filters as well as all the bits and pieces that are required to set everything up.

Overall, the system is quite easy to install. All you need is some patience, and you want to make sure to follow every single step as disclosed in the user manual – especially when it comes to installing the hoses.

If you’re not sure about the next task don’t hesitate to contact Aquasana’s friendly customer service. From our experience, they are more than happy to answer all your questions and help you out as good as they can.

That said, in case you’ve never drilled a hole before and you haven’t heard of a tool called wrench, then it’s probably a better idea to have a professional do the installation for you.


Warning: The music is a bit annoying.

Parts List

  • RO module with filter and membrane housings
  • Carbon filter cartridge
  • Claryum filter cartridge
  • RO membrane
  • Remineralizer
  • Brass tee
  • Drain saddle
  • Water storage tank (3.2 gallons, white)
  • Tank stand
  • Tank connector
  • Faucet of your choice with quick connector
  • Color-coded tubing
  • Plumber’s tape, nuts, bolts, screws, bracket, foam seal, washer, gasket, spacer, eye dropper
  • Flow restrictor
  • 90° elbow

Filter/Membrane Replacements

Aquasana’s OptimH2O reverse osmosis water filter system is definitely low in maintenance. The filters housings twist easily on and off. And we have quick-connect fittings. Both makes changing the filter elements a painless process.

Here’s how often you need to replace each component as per manufacturer specifications:

  • Carbon pre-filter: About every 6 months or 365 gallons
  • RO membrane: Every 1 to 3 years
  • Claryum post-filter: About every 6 months or 365 gallons
  • Remineralization filter: Every 12 months

Annual cost? Approximately $180-220 depending on your water quality and usage which is more than what you pay with most of the competition. At least you can join the Water for Life replacement filter program to receive replacement filters on schedule and at a discounted rate.


Here is a link to the Aquasana OptimH2O system manual.

Aquasana OptimH2O Cons

We read about problems with leaking. The good news is Aquasana sends replacement parts free of charge.

What’s more, some people have had issues with the overall system quality. Although feeling durable enough, especially the dispenser that is part of the package seems rather flimsy. Switching back and forth between it and your regular kitchen faucet will make the difference even more noticeable.

A third con is the flow rate. It seems to be slower than what other RO systems provide.

Aquasana OptimH2O Review: Our Verdict + Best for

5 different NSF certifications for a single water filtration system effectively removing 88+ different contaminants, that’s hard to find. And let’s not forget that the Aquasana OptimH2O also adds healthy minerals to your water for optimum hydration and natural taste.

Most customers would highly recommend the system, saying everything works exactly as advertised and that Aquasana support is fantastic.

All that plus an affordable price tag make the Aquasana OptimH2O our #1 under sink reverse osmosis system ideal for producing clean and safe water for drinking and cooking. Our verdict: 4.5 stars!

This completes our Aquasana OptimH2O review. If you have any questions about the OptimH2O please don’t hesitate to leave a comment below!

About the Author Alexandra Uta

Alex is a content writer with an affinity for research and a methodical attention to detail. Since 2020, she has fully immersed herself into the home water treatment industry only to become an expert herself. Alex has been using water filters and similar products for years which has gained her lots of hands-on experience.
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