Three points about advice on water treatment can cause misunderstanding.
Firstly, there is no need to kill or remove all the micro-organisms in water. …
Secondly, in theory, no normal treatment method will produce infinitely safe drinking water. …
Thirdly, beware the use of words like ‘pure’, ‘disinfect’ and ‘protection’, common claims in many manufacturers’ carefully written prose. …
Treatment of a water supply:
Boiling: Boiling at 100 degrees C kills all organisms found in water except a few such as slow viruses and spores which are not dangerous if drunk. ... To make water safe for drinking you should bring water to a full boil for at least two minutes. ... Do not cool water down with untreated water.
There are broadly three germicidal chemicals used for drinking water treatment...
1) Silver. Completely harmless, taste free and very long lasting effect, protecting stored water for up to sic months. The sterlisation process is quite slow and it is necessary to leave water for at least two hours before use.
2) Chlorine. Completely harmless, fast acting and 100 per cent effective if used correctly. A minimum of ten minutes is req2uired before water can be used. ... If in doubt, we recommend that the period before use be extended to at least 20 and preferably 30 minutes.
3) Iodine. Fast acting and very effective, normally taking ten minutes before water is safe to use. ... Iodine can have serious, lasting physiological side effects and should not be used over an extended period.
These are just sketchy details, and I haven't covered filtration. But two final points.
One, I have personally used Zero-B in various situations with all kinds of water and ... well, I'm alive.
Two, if forced to take water from some outside source, choose quickly running water if you can.