How a hiking water filter works
All filters in this category use a hollow fibre membrane: a bundle of tiny tubes with pores of 0.1 or 0.2 micron. Water is pushed through the walls of the tubes, bacteria and protozoa like Giardia stay behind. Honestly, hollow fibre filters do not remove viruses, chemicals or salt. In most European mountains that is fine, but near farmland, villages or campsites you pick your source with care or add chemical treatment.
Which filter suits you?
- Katadyn BeFree: the filter sits in the cap of a soft flask. Fill it, screw on the cap and drink or squeeze. It has a fast flow and you clean it by shaking it in water. A good choice if you like to drink on the go.
- Platypus QuickDraw: a squeeze filter with a 1 litre reservoir that also fits standard 28 mm bottle threads, so you can build it into your own setup.
- Platypus DayCap: a filter cap for a wide-mouth bottle like a Nalgene. Handy for day hikes and travel, when you want to refill from any tap or stream.
- Care Plus Water Filter: small and affordable. Use it as a straw, on a disposable bottle or with the included 500 ml pouch. 62 grams and good for 3500 litres.
Tips for using a water filter
- Never let your filter freeze. A frozen membrane can crack and then it no longer stops bacteria. On cold nights it goes in your quilt or sleeping bag.
- Clean or backflush the filter regularly, most of the flow comes back.
- Use a separate bag or bottle for dirty water, like an Evernew Water Carry or a Platypus bottle from our water bottles.
Frequently asked questions
Do I need a water filter when hiking in Europe?
Many hikers drink untreated water from mountain springs and often that goes fine. But with grazing animals or people upstream, a filter of less than 100 grams is cheap insurance against a few days of stomach problems.
How long does a water filter last?
Check the rated capacity of each filter. The Care Plus is rated for 3500 litres and the Katadyn BeFree for about 1000 litres. The flow slowly drops over time and cleaning brings most of it back.
Does a water filter remove viruses?
No, the hollow fibre filters here stop bacteria and protozoa, not viruses. For travel in areas where viruses in water are a risk, combine the filter with chemical treatment.