>>189226Well, it's a safety factor. When I said 30 minutes, that's the maximum, not the time you should leave it. To give you an idea, an immunodepressed person, like someone with AIDS, can only drink water that has been boiled for 30 minutes. Those people have medication to compensate for that of course and can in fact drink any water, but still, after 20 minutes of boiling, water 100% isn't sterile. And above 30 minutes, well, it becomes useless.
So it depends on your own body. You're right to correct that by the time it boils, it's fine... for you. For me too actually. Hell, I can drink about anything without getting sick, I even caught Malaria and survived. Meanwhile, my GF gets sick below 4 minutes roughly, because yes I actually experiment with that. It's up to you to find the ideal time, 30 minutes just happens to be the 99,99% sure option.
And indeed, it doesn't remove heavy metals, nor pesticides and other chemicals, which is why filters and chemical treatment are a good idea to use along with boiling; filters work wonders with heavy metals and many chemicals, and chlorine reduces all drug-borne compounds by half.
It's also a bad idea to drink boiled water usually. There's plenty stuff in water you actually need: minerals, salts, oxydes, nitrates... some will evaporate, some will form crystals and other sediments that will stay at the bottom and that you won't drink.
Also don't forgot to stir it before drinking it, so you can add more oxygen to it. Unless you want to have the runs.
And about Lifestraws®: some anon once said he took part in an experiment. University grade experimentation, but still quite interesting. They concluded that many things got past its filter, most likely because the suction squeezes them out of the tiny holes they get stuck in, killing the purpose of the filter.
It's to be taken lightly, but still quite interesting.