Last week we looked at some natural methods of purifying water. However, sometime we don’t have the resources or time to apply these and sometime the water we are forced to drink is so much akin to the toxic urine from Satan’s own bladder that only technology can make it safe.
As with all things there are compromises with water filters. Be it cost, weight, bulk, effectiveness or speed. There are a number of specific manufactures and models so I’ll try and keep this general but will include links to examples of each.
Particulate – Not necessarily toxic but particulate, like mud, sand, dead beetles and random, suspicious lumps are not what you want to be drinking.
Protazoa – These are single-cell parasites and the group contains Giardia and Cryptosporidium, two of the most feared Gastro-Intestinal (GI) infections. Some pathogens can only be eliminated by more advanced filters
Bacteria – Much larger than viruses so relatively easy to filter. This group includes E.coli, a common cause of GI problems.
Virus – Smaller than bacteria, and therefore more difficult to filter, this group includes Hepatitis and Rotovirus
Chemicals – Chemical pollutant are wide ranging and are more common in urban, industrial or certain agriculture areas.
Your filter need not deal with all these. Research where you’ll use it, what the local risks are and get what you need.