Usually one tablet is enough for one quart of water. Double the dose for cloudy water. While the three methods described above will remove only microbes from water, the following two purification methods will remove other contaminants. Distillation will remove microbes, heavy metals, salts, most other chemicals, and radioactive dust and dirt, called radioactive fallout. Filtering will also remove radioactive fallout.
Distillation involves boiling water and then collecting the vapor that condenses back to water.
The condensed vapor will not include salt and other impurities. To distill, fill a pot halfway with water. The water that drips from the lid into the cup is distilled. Cover the gravel with a towel cut in a circle slightly larger than the bucket. Cover soil with a towel, place the filter over a large container, and pour contaminated water through.