Grayl Water Bottle Deep Dive Review

Best Filtering Water Bottle for Travel

GRAYL Ultralight


Buy the GRAYL Ultralight

With replaceable purifier or tap-filter cartridges, the Ultralight can turn some of the nastiest water into clear, clean, and safe H2O.

Grayl ULTRALIGHT Details:

  • Price: $69.95
  • Materials: BPA-Free materials made from polypropylene #5, food-grade silicone, TPE, ABS
  • Features: 
    • (1) Outer fill container to collect unfiltered/unpurified water
    • (1) Purifier cartridge (that lasts 300 presses or 40 gallons) 
    • (1) Inner press container that stores purified or filtered water
    • (1) Loop cap and non-slip base 
  • Capacity: 16oz
  • Weight: 11oz
  • Height: 9.625”
  • Warranty: 10 year warranty covering workmanship and materials 
  • Recycle Program: All cartridges are recyclable 
  • Replacement Purifier Cartridge (orange) Price: $24.95
  • Replacement Tap Filter Cartridge Price (blue) (2-pack): $29.95

Who is the Grayl ULTRALIGHT for? Minimalists, Urban Explorers, and Solo Travelers 

What We Love:

Simple, Cool-looking, & Effective

  • Easy to use: Fill, press, that’s it
  • Sleek style: The GRAYL Ultralight complements your ensemble, it doesn’t take away from it
  • Good consistent results: This bottle is the most efficient and effective purifier I’ve ever used; no pumping necessary and it’s fast
  • Minimalist design: GRAYL is a solid and minimalist design; you don’t feel like you’re carrying around a contraption with you
  • Removes the bad stuff: Purifier cartridges remove sediment, microplastics, and 99.99% of water-borne pathogens

What We Don’t Like:

Too Small & No Mouthpiece

  • The container is too small: When I’m very dehydrated and very tired, consuming 14 oz of water is a fraction of what my body really needs; although the Geo-Press is a larger option
  • No built in mouthpiece: You’ve got to unscrew the entire lid everytime you want to take a drink (also fixed with the Geo-press)
  • A bit pricey: The Ultralight isn’t cheap but it quickly pays for itself in single use water bottles not purchased
  • Too simple: A mouthpiece helps ensure you don’t come in contact with pathogens; drinking from the rim feels like I’m introducing risk 
  • The bit at the bottom: When I remove the inner press after drinking filtered water, there’s a bit of contaminated water remaining at the bottom, which is contained by silicon. However, it made my stomach turn a bit (especially if I drank really contaminated water). 

How does the Grayl ULTRALIGHT work?

The concept is very simple:

  1. Collect water into the outer fill container first and fill up to the line (if you fill above the line it will overflow as you filter it)
  2. Place the container on the ground or a low surface
  3. Press down with your bodyweight on the inner press (with the purifier/filter cartridge on bottom) until the cartridge reaches the bottom (roughly 15 seconds for the purifier cartridge, 7 seconds for the tap water filter)
  4. Don’t put your hand over the top of it as air needs to escape while you press
  5. Voila – you have 16oz of purified water

An Adventurer’s Best Friend

In my opinion, this water purifier bottle is seriously meeting the challenges of the times we’re living in right now.

Microplastics are being found everywhere from the Arctic to the highest peak in Wales and even in bottled water. For those of us who adventure outside the confines of areas with potable water on tap, the GRAYL Ultralight is a necessity.

I felt comfortable knowing that GRAYL is surpassing EPA regulations with its design and is smart in its use of ion exchange and activated carbon to ensure metallics, 99.99% of pathogens, microplastics, and other undesirables are removed from the water I consumed.

This speaks to another thing I personally appreciated with GRAYL’s messaging; they’re aware that the vast majority of the world does not have access to potable water. However, I’d go further than them in their messaging and say that even where there is potable water, it should still be questioned.

GRAYL is making grade A water accessible and simple. It kind of blew my mind given the nightmares I’ve had of using water purification tablets on the go, or having to go out of my way to get huge cases of bottle water when I’ve lived in countries that don’t have potable water coming out of the tap. 

Also, I think my Amber GRAYL Ultralight is as slick as [90s] Brad Pitt in a tuxedo. No, there’s no other way to put it. I love packing this thing away in my Setout Backpack and it blends in perfectly and fits perfectly in the side water bottle pouch.

This is a solid product with a very minimalist and nonchalant design. There are four pieces that make up the design (cartridge, cap, inner press, and outer fill container). Remember, if you’re around potable water and want a bigger container, you can remove the cartridge and ‘shazam!’, you have about a fifth more space. On top of it all, it was really easy to figure out, even without instructions.

I wish I had my GRAYL Ultralight this time last year when I was traveling in the Horn of Africa, or two years ago when I was constantly buying bottled water or when I was living in New Orleans where the tap water seriously cannot be trusted. I did take this GRAYL into its more extreme water filtering territory when I went on a couple hikes in eastern Scotland. I was probably too excited to try it out on some local creeks, puddles, and even a bog or two. At first my brain did a couple somersaults when I drank purified bog-water as I’m sure my primal instincts were screaming ‘it can’t be that easy to make that crappy water clean and tasteless!’ Eventually I just came to trust the madness of how well GRAYL’s technology works. 

The Purifier Cartridge vs. the Tap Filter

GRAYL deserves a shout out for thinking about urbanites who don’t do a ton of hiking when they produced their tap filter cartridge. This cartridge takes a shorter amount of time to filter tap water (7 seconds) and uses the same technology to go a step further than municipal water treatment stations.

Changing cartridges is simply a matter of unscrewing the orange purifier cartridge from the Inner Press and replacing it with the blue purifier cartridge.

I did find the shorter amount of time required to clean water with the filter cartridge encouraged me to use the GRAYL more. As a result, I found that I used the filter cartridge more as I’ve been in Rome and Berlin the past couple months where the tap water is quite coarse, overtreated, and not totally trustworthy. For adventurers who would use a GRAYL for weekend hikes, getting tap filter cartridges is a wise move so you can prolong the life of your purifier cartridge (for truly dirty water) and then can use your tap filter cartridges when you’re at the gym, work, or even home. 

A Couple Downsides: Cross-Contamination and Size

Though I know GRAYL fixed this with their new and improved GeoPress Purifier, I had a problem drinking out of the container I collected heavily contaminated water in. My solution was to overfilling the outer fill container so that when I filtered with the inner press, the overflow would clean the outside of the bottle too. The GeoPress Purifier offers a mouthpiece which essentially fixes this problem.

When I used my purifier cartridge with heavily contaminated water, there was consistently leftover unpurified water at the bottom. Luckily there is silicone surrounding the cartridge to keep that water isolated. However, it just left my stomach and hypochondria unsettled. My current solution is to just pour the purified water into another container if I’m working with water that might make me sick. 

By the end of a 9-mile hike, my tired brain and body didn’t feel like pumping water as I really needed a more substantial amount after letting myself get dehydrated. 

The GRAYL Ultralight is just a bit too small for my liking. It’s a problem easily overcome by pressing and pouring into another water bottle to ensure a large enough supply of fresh water to get through the day.

GRAYL Ultralight: Things to Know

Cartridges Need Replacement

Your GRAYL Ultralight will come with one purifying cartridge. Tap filter cartridges must be purchased separately. Your used cartridges can be returned for recycling when you reorder. The cartridges cost $24.95 each for the purifier cartridge and $29.95 for TWO tap water filters.

Does Not Work on Ocean Water

No, the GRAYL does not filter the salt out of ocean water. Use it on fresh water only.

Note: desalinization is much different than fresh water purification. I did test ocean water in the bottle to see if the salty taste lingered in case the mistake was made. It did.

Lifespan of the Cartridges

Though I have yet to reach this point, the company does state that once it takes longer than 25 seconds with a purifier cartridge to filter the water, it’s time to replace it. The GRAYL Ultralight will filter about 40 gallons of water, that’s about 300 uses.

How the GRAYL Was Tested

I’ve been a travel writer with Tortuga for a couple of years and spend a lot of time traveling to places that have sketchy water supplies (cough*Africa*cough) as well as places that have decent city water but that I still wonder about (cough*Europe & North America*cough). I’m committed to lowering my carbon footprint and single use plastics so a filtering water bottle is a must have piece of gear, no matter where I’m traveling.

This water bottle has been my baby for the past few months and has travelled with me from Italy to Germany to the wee town of Anstruther where I live in Scotland.

I have used it for everything, from hiking along the Fife Coastal Trail, to helping me deal with dodgy tap water at hostels and apartments in Rome and Berlin, to using it on board trains and planes along the way. I even used it on dog water (I was bored).

As an anti-plastic waste traveler as well, I feel like I’ve given this bottle a serious test in a relatively short period of time. I really don’t like buying bottled water so I was filling up my GRAYL wherever I could along the way.

To be honest, there were some times where I had to take a leap of trust in drinking what my GRAYL filtered – which included purifying some bog water which I’m pretty sure had some cow poo in it. And yet, I am here to tell the tale. 

Key Concerns While Testing

When I first got the Grayl, there were several key questions I wanted to answer before giving it my seal of approval:

  • Accessibility: Straw purifiers are a pain in the butt and water purification pills make water taste nasty. Can water be purified while mobile and most importantly while tired? Does this make me more tired and does this affect when I should filter my water? 
  • Value: Is the GRAYL worth the investment for those of us living in near accessible potable water? Will this be used regularly or sit on a shelf? 
  • Effectiveness: Probably a question that can only be asked after trying it out with contaminated water – will I be sick? Will this water smell or taste weird in a way that may force me to shelf it? Is there a chance I may accidentally consume contaminated water?
  • Versatility: Can I use this product in more scenarios than just a hike? And will this product be accepted in more urban environments (gyms, offices)? 

What Makes Me an Expert?

Admittedly, I’m not a trained expert in water purification. I’ve had to rely on water purification methods and mechanisms often for my work, travels, and adopted homes, which tend to be in locations without reliably safe water sources, from the deserts of Somaliland and Northern Kenya to the ‘boil water advisory’ city of New Orleans. In addition to that, I’ve worked with communities during my travels struggling to access good potable water. So I look at portable water purification and filtration as the frontline of public health, not just as luxuries. 

On top of that, I think about how today’s water purification systems are addressing the environmental obstacles of current times. While I’ve been a writer for Tortuga for a few years, I’m simultaneously doing my PhD on climate and environmental policy, and I’m trying to constantly keep up to date with the impact of pollution on food and water supplies. As a result, I’m very keen to learn about the newest technology that is stepping up to making sure humans get access to clean, safe, and ‘as micro-plastic free as possible’ H2O. 


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