>>2041458Filters, chemicals, or boiling. Or UV light, which is a new technology.
Filters are fast. They don't remove viruses, but viruses are rarely an issue in 1st world nations. Somewhat expensive, can break, needs maintenance (backflushing).
Chemicals are small (a couple of pills or a dropper bottle) and inexpensive. They also kill viruses. They are slower to act (an hour or more), especially in cold weather. They may impart taste to the water.
Boiling is simple, and kills all. Can use a lot of fuel though, which is a concern or longer trips, and is as fast or slow as your stove is. Refilling a water bottle with scalding water might not be feasible depending on your bottle type.
UV light is battery powered (can run out). It's fast, and these days supposedly as good as a filter. I think it kills viruses too. Early models were prone to breaking or were finicky. They're expensive.
A couple of scenarios:
- muddy water - boil it and let the mud settle
- glacial runoff (silt) - avoid, the rock dust gives you the runs. Might work if you boil.
- ponds, lakes, water with debris, algae or larvae in it - pre-filter through a bandana, t-shirt etc to remove large particles which your system cannot handle.
- fast-moving, clear streams - bingo! But still use your purification system, a dead animal could be polluting the stream 50 yards off trail.
- stinky, miscolored water (cow throughs, tannins from wood etc) - your purification system will remove pathogens, but not taste or other dissolved substances (e.g. agricultural runoff with pesticides). A flavored drink powder can mask unpleasant taste, but will obviously not remove harmful substances.
