The Science-Powered Bottle: OKO H2O Level-2 Advanced Filtration Bottle Review

OKO H2O Level-2 Advanced Filtration Water Bottle Review PhotoFiltered water bottles have always been a popular topic here at Hydration Anywhere. It is something that just makes sense: why not have a device which not only carries your water, but also ensures you are drinking the cleanest water possible? This is the dream of the filtered water bottle. Yet when you get down to the realities of what is available, things look a little different. As we explored in our Filtered Water Bottle Buyers Guide, most filtered water bottles have some caveats: you might get a super-powerful filter but pay a pretty penny for it, or find something stylish and usable everyday but with a tap-water only filter.

But now there is a bottle which seems to tick all the boxes for our vision of what the filtered water bottle should be. Meet the OKO H2O Level-2 Advanced Filtration Bottle. Highly affordable, super portable, made from a durable, flexible, and squeezable BPA-free plastic, the OKO H2O bottle is equipped with a remarkably powerful filter capable of removing harmful bacteria and viruses as well as chemicals such as chlorine, lead, and other tap water contaminants. Let’s learn about the bit of high tech science which makes this bottle’s filtration so noteworthy.

The OKO H2O’s Game Changing Advanced Filtration

OKO H2O Advanced Level 2 Replacement FiltersThe quality of the filtration which the OKO H2O offers is undeniably superior to any filter bottle in its price range. The OKO H2O is capable of filtering water from most sources, be it removing potentially harmful bacteria from a river or stream, getting rid of nasty germs and sediment from a dirty puddle, giving questionable well- or tap-water a final treatment, or just making sure the office water cooler is as fresh and tasty as can be. Because the bottle’s filter is able to filter both microorganisms and chemical contaminants, it is an ideal solution for an all-in-one everyday carry filter bottle.

Considering the OKO H2O Level-2 Advanced Filtration Bottles are only about $20-$30 depending on which size you select, this is a pretty amazing accomplishment. It turns out that there is a whole lot of ingenuity behind the filters in this bottle. Using technology originally pioneered for use by NASA on the International Space Station, the OKO’s filter manipulates a clever principle of physics to make its already tiny 2-micron pore size even more effective at trapping contaminants.

For a bit more of a technical look at how this works, check out this quote from the OKO H2O Website:

“In addition to a 2 micron pore size, the material utilizes a positively charged electro-adsorption (attraction and retention) process to draw and trap harmful agents much smaller than its pore size. Charge fields, activated upon water contact extend 1 micron each to virtually close the pore to any intruding agents. ÖKO level-2 filter lab tests reflect removal of 99.994% of e-coli, 99.9999% of cryptosporidium and giardia lamblia, the most commonly found bacteria and microorganisms in lakes, streams and international water sources. A stack of over 400 such pores in the 0.8mm thickness of the filter create a “tortuous path” which a harmful agent would have to travel through in order to make it across the filter membrane. For detailed chart of the OKO Level-2 filter performance click here.”


A Multi-Purpose Filter Bottle

OKO H2O Bottles in Three SizesWhat catches our attention most about the OKO H2O is its remarkable versatility. Unlike some of its competitors which seem more like a piece of camping gear than an everyday water bottle, the OKO offers advanced filtration while remaining simple and stylish enough to be something you can use everyday. The sky is pretty much the limit when it comes to how you can put your OKO to use. As a companion on hikes or camping trips it is lightweight and unobtrusive to carry, opening up just about any water source except for saltwater. In an emergency situation it could become a lifesaving tool, or potentially spare you from illness when traveling to locations with questionable drinking water.

But even if you don’t leave town, or even your house, the OKO H2O bottle can still be plenty useful. Even though I love taking the OKO on adventures, it still gets use at home where I’m not a fan of the taste of the tap. Out on the town it serves a similar function giving me the peace of mind that my drinking water is as contaminant free as can be. The effect is most pronounced in my home, where I am very used to the rather unpleasant taste of the tap water. The OKO is just as effective at removing the taste and odor from my water as some much more expensive filter solutions I’ve tried.

For a pretty impressive visual demonstration of the filter’s abilities, check out this short clip from OKO. It demonstrates the OKO H2O Level-2 Advanced Filtration Bottle turning a soda into clean water.

A Simple and Highly Functional Design


The bottle itself on the OKO seems simple almost to a fault. Made from a squeezable transparent BPA-free plastic, there is a deceptive simplicity in the minimalism of the OKO bottle’s appearance. At a glance, the only real features of the bottle itself is its ergonomic curvature and the inclusion of some indentations to help improve grip. These features work well, making the bottle comfortable to carry and easy to squeeze.

Being able to squeeze the OKO bottle is part of its genius. This allows you to pass water through the filter without having to rely on suction or any kind of external pressure or pump. In contrast to something like a LifeStraw, this capability allows the OKO Bottle to act as more than just a personal filter, providing a way to filter water for sharing or different uses.

Minor Gripes

OKO H2O Advanced NASA ISS Scientific Water Filter Replacement Cartridge CloseupDespite being an undeniably space-aged product, the OKO H2O Bottle does still have a few shortcomings. Probably the most common complaint is its slow flow-rate: it takes awhile for water to pass through the filter, so it can leave you waiting. While a little inconvenient this is not much of a price to pay for the quality of filtration on offer and it doesn’t really bother anyone here at the blog. However, a bit more of an issue is the filter lifetime. Apparently the OKO wasn’t exactly built to last, since it only filters 100 gallons in a single filter lifetime. For the best taste, or depending on how dirty the water you’re filtering is, the manufacturer recommends swapping out the filter after just 50 gallons.

100 gallons might not seem too bad, but compared to some similarly priced filtering products it is rather abysmal. The Sawyer Mini Portable Water Filter (which is not a water bottle, but a similarly-priced and similarly-portable filtration solution) can handle a whopping 100,000 gallons in a single filter lifetime with proper care. OKO’s more expensive competitor the LIFESAVER Bottle filters upwards of a thousand gallons, and even the LifeStraw Go Bottle (which is only marginally more expensive than the OKO) has well-over double the filter lifetime.

So, if filter longevity is important to your purchasing decision, the OKO H2O might not be the best pick. When you exhaust the 100 gallon filter lifetime, replacements are around $10.


One other major complaint we’ve seen mentioned a lot in Amazon reviews is the OKO encountering problems with leakage after extensive use. Out of the box and after a few weeks of use and testing, our OKO H2O Bottles do not leak, even when inverted and shaken. But many users complain of encountering issues where the plastic gasket on the caps interior begins to warp, causing the seal to fail.

So far we have not encountered this issue, but it appears to be something frequent users have run into. Definitely a durability concern to watch out for! In the hopes of preventing this treat the cap and seal gently when removing or replacing the lid.

Using the OKO H2O Bottle

OKO BPA and PHT Free LogoThe mouth of the OKO is not too slim, which makes filling and cleaning the bottle pretty simple. The bottle itself also happens to be dishwasher safe, but be sure not to put the filter element in the dishwasher or get any soap on it or it will be ruined. Because it is a filtering bottle designed to filter water which exits the bottle, the water stored inside the OKO is contaminated water and you should never drink directly from the bottle without passing through the filter if you’ve filled it from a questionable source.

Portable enough for everyday use and easy enough to clean, the usability of the bottle is great. The cap easily unscrews with a few twists and filling the bottle from a stream, tap, or even a puddle is an easy process.

The OKO H2O In Action

The clip above showed us the manufacturer giving a neat demonstration of the OKO’s filtering ability, but how does it work out in the real world? Check out this great YouTube demonstration from user Matt Loynd as he puts his OKO to the test by drinking from a muddy puddle!

Review Summary

OKO Level 2 Advanced Filtration Water Bottle Product PhotoThere is a lot to like about the OKO H2O Bottle. Extremely affordable, offering high quality-filtration, a well-manufactured product, and a neat look for less than $30. Yet the filter lifetime is a bummer, and definitely the OKO H2O’s major failing point. As amazing and high-tech as their filters are, they just don’t have much in the way of stamina!

However, the lifetime isn’t so bad as to shelve the OKO Bottle. Actually, for a lot of people who buy it, the 100-gallon lifetime might be more than you ever bother to use, and the replacements are less than half the price of the bottle, so things aren’t all bad.

At the end of the day we are huge fans of the OKO H2O Bottle. We award it 4/5 stars, knocking one point off for the filter lifetime.

Learn More About the OKO H2O Level-2 Advanced Filtration Water Bottle

To see what other customers think of the OKO H2O, check current prices, learn more specifics, or purchase your own OKO H2O filter bottle, head over to the Amazon listing.

More from OKO H2O

OKO H2O Odyssey 6-in-1 Filter Bottle Disassembled with Flashlight and Drinking CupOKO has some other nifty filtering bottles on offer. Their OKO H2O Pure Everyday Water Bottle is a sub-$10 super-affordable bottle equipped with a simple coconut carbon filter. It doesn’t have the advanced filtration of the Level-2 bottle we reviewed above, but it is ideal for removing contaminants from tap water and making every drink a little healthier and tastier.

Another bottle from OKO which does include their Advanced Level-2 Filtration is the OKO H2O 6-in-1 Water Bottle (pictured right.) We have yet to get to try one of these bottles for ourselves, but the list of features is intriguing. Combining OKO’s Advanced Level-2 Filtration technology with a flashlight and portable drinking cup, the bottle aims to serve as a hiker or survivalist companion for outdoor adventures.

Click here to see what else OKO has to offer!


Best-in-Class Filtration
Quality Manufacturing
Affordably Priced


Possible Leakage After Wear
Low Filter Lifetime

  • Editor Rating
  • Rated 4 stars
  • 80%

The OKO H2O Level-2 is a filtered water bottle packing an amazing, space-aged filtration system in an extremely portable and affordable package.

1 thought on “The Science-Powered Bottle: OKO H2O Level-2 Advanced Filtration Bottle Review”

  1. I really interested form last years…I think this water bottle is really need for travelling times..where ever I mean..


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