Grayl Geopress and Ultralight Compact Water Filters Review

Having a solid water filtration system can make or break your next backpacking trip. Pack an easy and reliable filter, and you’ll stay hydrated and safe from harmful bacteria throughout the trip. Bring along a not-so-dependable option, and you’ll dread getting water and consequently become dehydrated.

My go-to filter, unfortunately, cleaned its last liter of water earlier this season. It had been a few years since I had been in the water filter market, and I was excited to try out some new options. As I was shopping around, I stumbled on Grayl water filters and was lucky enough to try out two of their products during the last few months. The two filters—the Geopress and Ultralight Compact— were designed for international travelers and backpackers, respectively.

Circumstances of Review: I tested both of these Grayl water filters in the Rocky Mountains of Colorado. They came along with me on summer day hikes and backpacking trips alike, and have been my go-to water filters throughout the summer 2020 season.

Grayl Geopress Water Purifier Bottle – 24 fl. Oz.

  • MSRP: $89.95
  • Weight: 15.9 oz
  • Output: 24 fl oz per 8 seconds (5L per minute)
  • Removes: Protozoa, bacteria, viruses
  • Cleaning: Replace cartridge after 250L

Being heavy and a little bit larger than is preferred for backpacking, I mainly tested this filter on car camping and day hiking adventures. The unique thing about Grayl water filters is that the filtration device doubles as a water bottle, which makes it easy to store extra water during dry stretches of trail. The lid on the bottle is designed to function as not only a way to store water, but also includes a small removable cap to make it easy to drink directly from the filter.

The water filter works by filling up the bottle with dirty water and pressing the geo-press down into the cup. As the filter slowly moves down into the dirty water, clean water appears on the other side ready for drinking.

The system is simple enough. However, I did find it a little bit challenging to press the filter down into the cup and through the water. It required me to put almost my entire body weight into filtering, and after a long day of hiking, this wasn’t always ideal. That said, I was able to filter 24 fl oz at a time with this model, so ended up with a decent amount of water for the effort.

As far as durability goes, the filter was built to withstand almost anything you throw its way. Grayl says it will hold up to a 10ft drop on concrete – even when full of water. Although I did not test this claim out myself, I didn’t have any problems with durability and overall, the entire filter feels very tough and sturdy when using.

Shop the Grayl Geopress Bottle

Grayl Ultralight Compact Purifier Bottle

  • MSRP: $69.95
  • Weight: 10.9 oz
  • Output: 16 fl oz per 15 seconds (2L per minute)
  • Removes: Protozoa, bacteria, viruses
  • Cleaning: Replace cartridge after 150L

 With a smaller size and lighter weight than the 24oz Geopress above, the Ultralight Compact Purifier is designed with backpackers in mind. The filtration system works exactly the same as the larger version, with hikers pressing down on the Geopress to filter water. It weighs less because the bottle is smaller and the lid is less intricate than the Geopress. However, this simple cap design allows you to attach it to carabiners and hooks on your backpack for easy access while hiking.

Compared to popular water filtration devices among thru hikers, this filter is heavy and doesn’t offer the option to filter more than half a liter of water at once. I typically had to filter multiple times to fill my Smartwater bottles while on trail. That said, the Grayl Ultralight shines in stagnant water sources where filter bags for Sawyer and Katadyn BeFree models would sometimes have issues filling without flow. As with above, it’s also convenient to have this filter double as a drinking bottle if you wanted to bring extra water back to camp or were approaching a dry section of trail.

Shop the Grayl Ultralight Compact Purifier Bottle

Overall Value

Although technically different products, the main variation is the size and weight between the two filters – all other functional parts are the same. That said, filtering water through the various Grayl water filters is a simple concept that ends up taking a little more effort than filtering through its competitors’ products. However, the filter shines in still and stagnant water, and the option for the filter to double as an additional water bottle is great. It also removes viruses (including norovirus), a capability that sets Grayl apart from the competition. Although the weight is heavier than many other water filter options, I think the filter still works really well as an option for car camping or day hikes. I plan on continuing to use this on my casual trips so as to not wear out my UL equipment.

Comparable Filters

Sawyer Squeeze

  • MSRP: $36.95
  • Weight: 3 oz
  • Output: 1.7L per minute
  • Removes: Protozoa, bacteria
  • Cleaning: Backflush (filter not replaceable)

Katadyn BeFree

  • MSRP: $44.95
  • Weight: 2.3 oz
  • Output: 2L per minute
  • Removes: Protozoa, bacteria
  • Cleaning: Shake/swish to remove debris; replacement filters available (each can last up to 1,000L)

These items were donated for purpose of review.

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Comments 4

  • Russ1663 : Oct 30th

    Hi Colleen. As I have been using both Grayl bottles for some time I throughly agree with your assessments. Keep the Ultralite in a go bag in the car. The Geopress in with my day pack in my truck. It doubles up with a Nalgene that has electrolyte mix. Safe travels to you.

  • David626 : Aug 31st

    You missed a key differentiator. The Grayl units are purifiers, not just filters. The Grayl units remove heavy metals and chemicals such as fertilizers which the other units do not.


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