Reader rating
Rate it and you move it. Community ratings re-rank this product inside its Top 10 list.
Expert-picked, reader-ranked. Our editors choose the products and the launch order; member star ratings move picks up or down over time.
The Platypus Hoser is a stripped-down classic that has earned a loyal following among thru-hikers and ultralight backpackers for decades. At less than 4 ounces, it eliminates virtually all unnecessary hardware, eschewing large molded handles, bulky plastic sliders, and quick-disconnect ports in favor of a clean, minimalist design. For anyone counting every fraction of an ounce on a long-distance trail, the Hoser is one of the lightest complete reservoir setups you can buy. Where the Hoser truly excels is water taste. Platypus uses a taste-free polyurethane blend that leaves zero plastic or chemical residue in your water, even when exposed to warm sun over long stretches of trail. The reservoir utilizes a standard 28mm threaded neck, which aligns with popular ultralight squeeze filters like the Sawyer Squeeze. This allows experienced hikers to screw their filter directly onto the reservoir for simple, no-fuss water collection and gravity-filtering workflows. The trade-off for this simplicity is maintenance. The narrow threaded opening makes the Hoser frustrating to fill at shallow wilderness seeps, and drying the bladder out requires patience because you cannot reach inside with a towel. The basic push-pull bite valve also lacks the high flow rate and positive locking mechanisms found on heavier, modern reservoirs. Still, its featherweight reliability and pristine water taste keep it a staple on extended trails. **Highlights** - Ultralight construction weighs less than 4 ounces for a full system - Taste-free film eliminates unpleasant chemical flavors from day one - Standard 28mm threaded opening is directly compatible with popular backcountry water filters - Soft, flexible body rolls up compactly when empty to save space - Simple push-pull valve reduces mechanical failure points **Watch-outs** - Small threaded opening makes filling from shallow creeks and cleaning interior tricky - Air drying takes significantly longer due to narrow neck opening - No quick-disconnect hose feature means the entire tube must be pulled from the pack
Pros
- Ultralight footprint under 4 ounces
- Consistently neutral, taste-free polyurethane film
- Standard 28mm threading pairs directly with squeeze filters
- Packs down completely flat when empty
Cons
- Small opening makes cleaning and air drying tedious
- Difficult to fill quickly from shallow water sources
- No quick-disconnect feature on the drink tube
Best uses
- Ultralight backpacking
- Thru-hiking
- Gravity filtration setups
- Minimalist day hiking
Specifications
- Weight
- 3.8 oz
- Dimensions
- 16.5 x 7 inches
- Closure Type
- 28mm threaded screw cap
- Valve Style
- Push-pull bite valve
- Approximate Price
- $40
Pricing
We don't publish a price we haven't verified. The retailer links below open the live listing for this exact model.
Full catalog listing & offersBest for
Ultralight backpacking, Thru-hiking, Gravity filtration setups, Minimalist day hiking
Where to buy the Hoser
Prices and stock change often, so check the current Amazon offer before you buy.
Some links are affiliate links. Buying through them supports our testing at no extra cost to you.
The Platypus Hoser represents an ultralight, stripped-down philosophy that prioritizes bare essentials over modern conveniences. Weighing roughly 3.8 ounces for the reservoir and hose assembly, it shaves significant weight compared to traditional full-featured bladders. Rather than incorporating heavy molded handles, wide slide-top closures, or bulkier quick-disconnect valves, Platypus relies on a simple threaded port and welded film body. This minimalist build has made it a long-standing favorite on long-distance thru-hikes where base weight reduction is a primary concern. Water quality is a major draw for the Hoser. The proprietary polyurethane film used by Platypus has consistently earned accolades across independent gear tests for being virtually taste-free right out of the box, avoiding the chemical and plastic notes common in other reservoirs. Furthermore, the 28mm threaded opening matches standard backcountry squeeze filters, allowing hikers to integrate the bladder directly into inline or gravity filtration setups. However, stripping out hardware means living with distinct usability compromises. The narrow screw top makes filling difficult in shallow water sources and renders interior cleaning or towel drying impossible. Flow rates through the basic push-pull bite valve are also modest compared to high-flow switch valves. For hikers who value clean-tasting water and low pack weight above all else, the Hoser remains a compelling, time-tested option.
Target Audience
The Hoser is tailored specifically for thru-hikers, ultralight backpackers, and minimalist adventurers who tally every fraction of an ounce. It appeals to users who prioritize low weight and packability over ease of cleaning or fast fills. If you regularly use squeeze filters with standard 28mm threading and want a clean filtration system without carrying extra adapters, this reservoir fits neatly into your kit. It is less suited for casual day hikers, runners, or mountain bikers who prefer quick disconnects and fast refilling at trailhead fountains.
Materials and Construction
Platypus constructs the Hoser using a flexible, puncture-resistant polyurethane laminate that is 100% BPA-, BPS-, and phthalate-free. Embedded silver ions provide natural antimicrobial protection to inhibit mold and bacterial growth over long stretches on the trail. The seams are radio-frequency welded for high burst strength under pack compression. At the base, a reinforced threaded collar mates cleanly with the included hose assembly, avoiding complex mechanical joints that might crack or fail during rough handling in a tight pack.
Taste and Water Purity
One of the most persistent complaints regarding hydration bladders is the lingering taste of plastic, particularly when water warms up during long days in the sun. The Hoser consistently stands out across independent testing for delivering completely neutral, clean-tasting water from the first fill. Its interior film resists absorbing flavors, meaning you do not have to endure chemical aftertastes. This makes it an ideal bladder for hikers sensitive to off-flavors who rely on natural backcountry springs for replenishment.
Filtration and Compatibility
The standardized 28mm opening is a standout utilitarian feature. Because it shares threading with popular hollow-fiber squeeze filters like the Sawyer Squeeze, the reservoir doubles as a clean-water collection bag or a gravity-fed reservoir. Hikers can thread a filter directly onto the opening to drink immediately, or run an inline setup through the drink tube. This dual-use functionality eliminates the need to carry duplicate water bladders, simplifying camp workflows and trimming gear bulk from your pack.
Maintenance and Trade-offs
The primary disadvantage of the Hoser is the small opening. Filling from slow-moving or shallow water sources requires patience, a scoop, or a separate collection vessel. Cleaning requires bottle brushes or specialized tablets because you cannot reach an arm or sponge inside. Drying the bladder is equally demanding; without a wide top or integrated drying arms, moisture lingers in the interior corners for days unless propped open deliberately. Additionally, the lack of a quick-disconnect tube means you must re-thread the hose through pack sleeves during refills.
Market Alternatives
At around $40, the Hoser competes against feature-rich reservoirs from brands like HydraPak, CamelBak, and Osprey. Models such as the HydraPak Shape-Shift offer slide-seal tops, quick-release hoses, and reversible bodies that turn inside out for dishwasher cleaning, albeit at a higher weight penalty. CamelBak's Crux offers significantly higher water flow per sip, but with bulkier molded components. The Hoser remains the choice for those who view those modern additions as unnecessary weight and potential failure points.
How we picked
We started with a long list of hydration bladders that people actually buy, cut anything that could not clear our baseline for durability and field performance, then ranked the 10 that were left against the same criteria. Rankings are editorial. No brand pays for placement, and affiliate links never move a pick up or down.
- Real-world durability
- How the material, stitching, or steel holds up after a season of hard use — not how it looks new.
- Performance in bad conditions
- Wind, rain, cold, and grit are the test. Anything that only works on a nice day gets marked down.
- Weight and packability
- Every ounce has to earn its place in the pack, but not at the cost of something that fails in the field.
- Ease of use
- Setup, adjustment, and maintenance with cold hands, in the dark, without the manual.
- Value at its price point
- Compared against the closest competitors in the same tier, not against cheaper gear in a different class.
- Repairability and support
- Field-fixable design, available parts, and a warranty the maker actually honors.
Hoser — frequently asked questions
- Is the Hoser worth it?
- We rank it #4 in Hydration Bladders. The Platypus Hoser is a stripped-down classic that has earned a loyal following among thru-hikers and ultralight backpackers for decades. At less than 4 ounces, it eliminates virtually all unnecessary hardware, eschewing large molded handles, bulky plastic sliders, and quick-disconnect ports in favor of a clean,…
- What is the Hoser best for?
- Best for ultralight backpacking, thru-hiking, gravity filtration setups and minimalist day hiking. Standouts: ultralight footprint under 4 ounces and consistently neutral, taste-free polyurethane film.
- What are the downsides of the Hoser?
- Small opening makes cleaning and air drying tedious, Difficult to fill quickly from shallow water sources and No quick-disconnect feature on the drink tube.
- What are the key specs of the Hoser?
- Weight: 3.8 oz · Dimensions: 16.5 x 7 inches · Closure Type: 28mm threaded screw cap · Valve Style: Push-pull bite valve · Approximate Price: $40
- Target Audience — what should I know about the Hoser?
- The Hoser is tailored specifically for thru-hikers, ultralight backpackers, and minimalist adventurers who tally every fraction of an ounce. It appeals to users who prioritize low weight and packability over ease of cleaning or fast fills.
- Materials and Construction — what should I know about the Hoser?
- Platypus constructs the Hoser using a flexible, puncture-resistant polyurethane laminate that is 100% BPA-, BPS-, and phthalate-free. Embedded silver ions provide natural antimicrobial protection to inhibit mold and bacterial growth over long stretches on the trail.
Compare side by side
Put the Hoser against any other pick on this list — specs, price, pros, cons and reader ratings.