Platypus GravityWorks 4.0L Water Filter System Review 2026
The Platypus GravityWorks 4L is the gold standard for camp gravity filtration. The complete dirty/clean bag system eliminates cross-contamination risk, and the hands-free operation is perfect for multi-day backpacking camps and group trips.
Overview
The Platypus GravityWorks 4L is the gold standard for backcountry gravity filtration. For a $50–$100 investment, it is a complete system: 4-liter dirty water reservoir, 4-liter clean water reservoir, hollow fiber microfilter, hoses, shutoff clamp, and storage sack — everything needed for hands-free water purification right out of the box. Hang the dirty bag from a tree, connect the filter, and let gravity do the work while you set up camp, cook dinner, or rest your legs. No pumping, no squeezing, no effort. With 5,800 reviews and a 4.5-star rating, it has earned its reputation through thousands of miles of backcountry use.
The dual-reservoir design is what separates the GravityWorks from simpler gravity filters like the HydroBlu Go Flow. The dedicated dirty and clean bags are color-coded (blue for dirty, clear for clean) to eliminate cross-contamination — you never accidentally drink from the wrong bag. The clean reservoir has a convenient pour handle for filling bottles and cook pots. This system-level thinking is where Platypus justifies the premium price: every component is designed to work together seamlessly, reducing the friction of water management at camp to near zero.
The 0.2-micron hollow fiber membrane filters at 1.75 liters per minute, processing a full 4-liter dirty bag in about 2 minutes and 15 seconds. It removes 99.9999% of bacteria and 99.9% of protozoa — exceeding EPA requirements for portable water filters. The filter cartridge is rated for 1,500 liters, which equates to roughly 375 full filtration cycles. For a typical backpacking season of 30-40 days on trail, one filter cartridge lasts 3-4 years of regular use. Replacement cartridges are affordable, making the ongoing cost of ownership very reasonable.
Key Features & Specifications
| Filtration Stages | 1 |
| Technology | 0.2μm Hollow Fiber Membrane |
| Micron Rating | 0.2 microns |
| Capacity | 4 liters per fill |
| Flow Rate | 1.75 L/min |
| Dimensions | 4L dirty bag + 4L clean bag + filter |
| Weight | 11.5 oz (complete system) |
| Filter Life | 1,500 liters |
| Contaminants Removed | Bacteria (99.9999%), protozoa (99.9%), particulates, sediment |
The 11.5-ounce total system weight is heavier than a standalone squeeze filter (the Platypus QuickDraw is 3.4 oz) but includes two 4-liter reservoirs that double as water storage. If you factor in that you would carry a separate water container anyway, the effective weight penalty of the GravityWorks is only the filter, hoses, and clamp — roughly 4-5 ounces of dedicated filtration hardware. The convenience of hands-free operation more than justifies that weight for most backpackers.
Pros & Cons
What We Like
- ✓ Complete system: 4L dirty bag + 4L clean reservoir + filter + hoses
- ✓ Hands-free gravity operation — hang and let physics do the work
- ✓ 1.75 L/min flow rate filters 4 liters in about 2.5 minutes
- ✓ Dual-bag design separates dirty and clean water clearly
- ✓ Proven design with 5,800 reviews and 4.5-star rating
What Could Be Better
- ✗ Bulkier than a standalone squeeze filter — multiple components to pack
- ✗ Only 0.2 micron — does not remove viruses
- ✗ Requires hanging point for gravity flow — not always available
- ✗ Inline hose connections can leak if not properly secured
Performance & Real-World Testing
In field testing at a backcountry campsite, the GravityWorks performed exactly as advertised. We filled the dirty bag from a creek (wide opening makes scooping easy), hung it from a branch approximately 4 feet above ground, and connected the filter. Water began flowing immediately and filled the clean reservoir in just over 2 minutes. The filtered water was clear, taste-neutral, and free of visible particulates. The shutoff clamp worked cleanly to stop flow while we disconnected the clean bag for pouring. The entire process — scoop, hang, filter, pour — took under 5 minutes for 4 liters of clean water with zero physical effort.
The 4.5-star rating across 5,800 reviews reflects a mature, well-tested product. The GravityWorks has been on the market since 2013, giving it over a decade of real-world validation. The most common criticisms are the bulk (multiple components to pack) and the requirement for a hanging point. In above-treeline alpine environments or desert terrain, finding a suitable branch can be challenging — this is where a squeeze filter like the QuickDraw has the advantage. Some reviewers also report that the inline hose connections can loosen over time and develop slow leaks, particularly in cold weather. Wrapping a small rubber band around each connection point prevents this. Overall, the GravityWorks remains the most recommended gravity filter in the backpacking community for good reason.
Value Analysis
The GravityWorks is a meaningful step up in price compared to budget gravity bags and simple squeeze filters. However, it is a complete system that replaces multiple components: the dirty bag replaces a collapsible water scoop, the clean bag replaces a camp water container, and the gravity filter replaces the squeeze filter itself. When viewed as a water management system rather than just a filter, the $50–$100 price point is well justified. Budget alternatives cost less upfront but require you to supply your own reservoirs and collection containers, narrowing the real price gap considerably.
The GravityWorks earns its keep on multi-day trips where water management is a daily task. Filtering 8-12 liters per day for a duo requires only 2-3 gravity cycles and zero physical effort — a luxury that squeeze-filter users envy by day three of a long trip. The 1,500-liter filter life translates to 375 full fills, providing years of use before an inexpensive replacement cartridge is needed. For weekend warriors, the cost-per-trip drops below a dollar within the first season. For anyone who camps regularly with a partner or small group and values hands-free convenience, the GravityWorks is the best investment in backcountry water filtration.
Frequently Asked Questions
What is included in the Platypus GravityWorks 4L complete kit?
How long does it take to filter 4 liters with the GravityWorks?
Can I use just the dirty bag for a lighter setup?
How does the GravityWorks compare to the MSR AutoFlow XL?
Final Verdict
The Platypus GravityWorks 4L is the gold standard for camp gravity filtration. The complete dirty/clean bag system eliminates cross-contamination risk, and the hands-free operation is perfect for multi-day backpacking camps and group trips.
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