| How it works | Gravity pulls water through the filter |
| Best for | Groups, large volumes, base camp |
| Strength | Hands-free |
| Trade-off | Heavier; needs a hang point |
A gravity filter uses gravity to pull water from a hung ‘dirty’ reservoir through a filter element into a ‘clean’ container, with no pumping or squeezing. It’s effortless and great for filtering large volumes for groups or base camp, but it’s heavier and slower per liter than a squeeze filter and needs hang points.
Gravity vs squeeze
Best water filter for groups; for solo, fast use a squeeze filter. Add a UV purifier or chemicals for viruses — see water treatment.
Frequently asked questions
What is a gravity water filter?
A gravity filter is a system with two reservoirs and an inline filter: you fill the 'dirty' bag, hang it up, and gravity drives the water down through the filter into the 'clean' bag or bottles, hands-free. It's ideal for producing lots of clean water for a group with minimal effort.
Gravity vs squeeze filter?
Gravity filters are effortless and excel at filtering large volumes for groups and camp, but are heavier and need somewhere to hang the bag; squeeze filters are lighter and faster for individuals and on-the-go drinking. Solo hikers favor squeeze; groups and base camps favor gravity.
Do gravity filters remove viruses?
Standard gravity filters remove bacteria, protozoa, and sediment but not viruses, since they use the same kind of filter elements. For virus protection, choose a model with a purifier element or add chemical treatment or UV to the filtered water.
Sources
- Water filters — American Hiking Society