Gravity Water Purifiers

Do you need a water filter or water purifier? 

• Filters: Remove protozoa (Cryptosporidium, Giardia) and bacteria (E. coli, Salmonella)—main concerns in the U.S. and Canada. 

• Purifiers: Also combat viruses such as hepatitis A, rotavirus and norovirus.  

Types of water filters 

• Straw: Light and easy to use, but only works when you're at a water source. 

• Bottle: Lightweight, quick and affordable. Water volume is limited by bottle size. 

• Gravity: Easy to use, handles large quantities of water, and has a replaceable element.

• Pump: Precise, works in shallow water sources and has a replaceable filter but bulky and requires cleaning.

• Ultraviolet light: Fast, no filter to replace; requires batteries and prefiltering for cloudy water. 

• Squeeze: Compact and affordable; water quantity is limited by reservoir size. 

• Chemicals: Inexpensive, ultralight backup method; long wait time and don't taste great.