Platypus GravityWorks

Do you need a water filter or water purifier? 

• Water filters: Physically remove protozoan cysts (like Cryptosporidium and Giardia lamblia) and bacteria (such as E. coli, Salmonella, Campylobacter and Shigella)—the main water concerns if you’re traveling in the U.S. and Canada. 

• Water purifiers: Go further by combating viruses such as hepatitis A, rotavirus and norovirus. 

Types of water filters 

• Pump filters/purifiers: Process precisely the amount of water you need, even from shallow water sources, and the internal element or cartridge is replaceable. Can be bulky and a chore to use and clean in the field. 

• Gravity filters/purifiers: Filter large quantities of water with minimal effort; replaceable element. Require finding a hang point, slower than pumping and harder to fill in shallow water sources. 

• Ultraviolet light purifiers: Easy and quick and never require element replacement. Require batteries, prefiltering for silty or cloudy water and multiple treatments for large quantities. 

• Bottle filters and purifiers: Easy and quick, have replaceable elements, lighter and less pricey than pump and gravity filters. Water quantity is limited by bottle size. 

• Squeeze filters: Easy, quick, smaller and less pricey than pump and gravity filters, have replaceable elements, sometimes usable as both a gravity and straw-style filter. Water quantity is limited by reservoir size. 

• Straw-style filters: Easy, quick, lighter and less pricey than pump and gravity filters. Limit water availability to generally one person and only when you’re at a water source, and not all models have replaceable elements. 

• Chemicals: Easy, inexpensive, ultralight backup method to purify water. Significant wait time before water is safe to drink and don’t taste great.