💧 Which method to make water drinkable?
What each method really eliminates (bacteria, viruses, protozoa, chemical contaminants), its cost in time, weight, and money — to choose before leaving, not when you're thirsty.
★ Only distillation also removes chemical pollutants and salt — no membrane filter or chemical disinfectant can do that.
★ An improvised charcoal/sand filter does not kill any pathogens: it clarifies, it does not sterilize.
★ Chlorine and iodine remain unreliable against Cryptosporidium; only chlorine dioxide, boiling, UV, and fine mechanical filtration can eliminate it.
★ Sawyer and LifeStraw do not trap viruses (pores are too large) — a real risk in surface water frequented by humans.