Do you need a water filter or water purifier?
Types of water filters
Gravity: Easy to use, filters large quantities of water, replaceable element. Needs a hang point, slower and harder to fill in shallow water sources.
Bottle: Lightweight, quick, replaceable element, less pricey. Water quantity is limited by bottle size.
Squeeze: Easy, quick, smaller and less pricey, have replaceable elements, sometimes usable as both a gravity and straw-style filter. Water quantity is limited by reservoir size.
Read full article: How to Choose a Water Filter or Purifier