Aquasana OptimH2O Reverse Osmosis Water Filter System Review (2020)

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    Aquasana OptimH2O

    Aquasana OptimH2O RO System

    •    Price: $
    •    Filter Stages: 4
    •    Gallons per Day: 35
    •    NSF Standard: 42, 53, 58...
    •    Annual Cost: $$$
    •    Warranty: 2 Years

    In this review, you will learn all about the advantages and drawbacks that come with the Aquasana OptimH2O RO filter system.

    The system features a 3-stage filtration process with an additional remineralization stage.

    • Stage 1: A basic 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. The benefit? You save money in the long run, because the membrane requires less frequent replacements.
    • Stage 2: The RO membrane reduces many potentially harmful impurities, such as fluoride (95.7%), nitrates & nitrites (82.40%), lead (96.6%) and pentavalent arsenic (97.6%).
    • Stage 3: A Claryum® carbon filter helps to eliminate 5 times more contaminants than the RO process would alone. This includes herbicides, pesticides, chloramines, pharmaceuticals and more.
    • Stage 4: Finally, it’s time to get those healthy minerals lost during the filtration back into your water. The mix of calcium, magnesium and potassium also helps to balance pH-levels and create a natural taste.

    The recommended pressure for operating the Aquasana OptimH2O is between 40 and 100 psi.

    Anything lower than that and you will have to use a booster pump or the filtration process will be ineffective.

    And lastly, at .5 gpm the system wastes about 4 gallons of water for every gallon filtered which equals a 17.91% efficiency. The flow rate is rather low compared to other RO systems, however, the filtered water to wastewater ratio seems about average.

    What We Like

    The full system is tested and certified to NSF standards 42, 53, 58, 401 and also conforms to NSF Protocol P473. We have to admit that we haven’t even heard of NSF Protocol P473 prior to reviewing this filtration system.

    Needless to say that, if you are looking for a water filter to finally get rid of a bunch of nasty contaminants lurking in your tap water, this is it!

    Aquasana reverse osmosis system reviews - OptimH2O

    →Click here to find out what other customers are saying

    Just for clarification:

    • Standard 42 tests for the ability of a filter to remove chlorine/chloramine and other particulates from water that create unpleasant taste and odors.
    • Standard 53 tests for reduction of contaminants with health effects. These include volatile organic compounds (VOCs), lead, cysts, asbestos, etc.
    • Standard 401 is for emerging contaminants that have found their way into our water systems only in recent years – think herbicides, pesticides, certain pharmaceuticals, detergents.
    • Standard 58 is specifically for point-of-use RO systems. The standard covers material safety, structural integrity, Total Dissolved Solids (TDS) reduction and other optional contaminant reduction claims.
    • Protocol P473 which we haven’t seen before is for PFOA and PFOS. The abbreviations stand for perfluorooctanesulfonamide and perfluorooctanesulfonic acids. Both substances are known carcinogens.

    Open the following tab to check out some of the reduction rates that the Aquasana OptimH2O was able to 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%
    Lead: 96.6%
    Nitrate/Nitrite: 82.40%
    Radium: 226/228 80.0%

    Standard 401

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

    NSF Protocol P473

    PFOA & PFOS: 96%

    All in all, the system is capable of removing up to 99% of 88 different contaminants. And as far as filtration capacity is concerned, the RO membrane can produce up to 35 gallons of water per day – in theory.

    Real-life daily system production is 13.32 gallons as per NSF Standard 58 (measured at 50 psi, 77°±2°F, and 717 mg/l TDS). This is not as much as you will get with many other models, but for regular use it’s more than enough.

    Last but not least, Aquasana offers a 2-year limited warranty on this product which got you covered in case something goes wrong.

    System Installation

    The full package includes the first set of filters, a lead-free faucet available in 3 different finishes (brushed nickel, chrome, oil rubbed bronze) to match your kitchen decor, and 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 hose. By the way, we really like the manual, because it’s straightforward and makes sense for a change.

    And if you are stuck, 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.

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

    This video explains the installation in great detail (we know the music is a bit annoying, but we couldn’t find a better one):

    Parts List

    • RO module with filter and membrane housings
    • Remineralizer
    • Carbon filter cartridge
    • Claryum filter cartridge
    • RO membrane
    • 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, spacer, eye dropper
    • Flow restrictor
    • 90° elbow

    Filter/Membrane Replacements

    This system is definitely low in maintenance. The carbon housings twist off easily, which makes changing the filters a painless process.

    Here’s how often you will have to change 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
    • Remineralizer: Every 12 months

    Please remember that these are rough guideline. The exact lifetime of each of the components depends on your water usage and quality. Also keep in mind that timely replacements will protect the RO membrane from high levels of chlorine and/or sediment.

    Annual cost? More than what you pay for maintaining most other RO systems.


    The Aquasana OptimH2O manual is available here.

    What We Don’t Like

    Here is what we don’t like:

    • Like we said, the flow rate with this filter system is slower than usual. Some people reported they had to wait 3 full hours to fill 2 glasses of water. That asks for some patience if the storage tank is empty!
    • Although feeling durable enough, the chrome faucet that is part of the deal is rather flimsy. Switching back and forth between it and your regular kitchen faucet will make the difference even more noticeable.
    • Some people complained about leaking.

    On a side note: The system produces 3 to 4 gallons of wastewater for every gallon of drinking water. The reason why we don’t consider this a drawback is because it’s simply how reverse osmosis filtration works.

    If this bothers you, consider buying an additional pump which helps to reduce water wastage by up to 80%. Another trick is to collect the remaining wastewater in a bucket and reuse it, for example to water your garden.

    Our Verdict

    We would recommend the Aquasana OptimH2O reverse osmosis water filter system to anyone who doesn’t want to make any compromises when it comes to drinking water quality. 5 NSF certifications for a single filtration systems, that’s hard to find.

    And let’s not forget that the unit adds bits of healthy minerals to your water for optimum hydration and great taste. Why “only” 4 stars? Mainly due to the pricey replacement filters.

    Looking for More Aquasana Information & Reviews?

    Here you can find reviews for all of Aquasana’s water treatment systems.

    Not what you are looking for? How about the best reverse osmosis under sink systems?

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

    About the Author Gene Fitzgerald

    Gene Fitzgerald has been with BOS since the very beginning. She is head of content creation and has fully immersed herself into the home water treatment industry only to become an expert herself. Outside of BOS, Gene loves reading books on philosophy & social issues, making music, and hiking.
    Learn more about Gene and the rest of the BOS Team.


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