Of all the things you can’t live without while on the trail, fresh water is right at the top of the list. Unfortunately, water is also one of the heaviest things you can take along and can weigh you down more than just about anything else you carry with you. The remedy to this problem is to purify existing water rather than carrying your own. Of the different ways to purify water, filtration is perhaps the simplest and most effective. Water filters include an internal element or cartridge that has microscopic pores that catch debris, protozoa, and bacteria as the water is filtered through it. Many filters also include activated carbon in their elements to remove unpleasant tastes. Different types of filters include pump filters, gravity filters, bottle filters, squeeze filters, and straw-style filters.