Boiling is recognized as a reliable way to purify water as the high temperature kills the germs and harmful elements in it. Boil the water in a kettle for ten minutes and allow it to cool down after it. Let the white particles settle down at the bottom, and filter the water out by tilting the kettle from one side into another container and not letting the particles leave the kettle. This is also the safest way to purify water as it does not contain addition of any second substance.
Liquid bleach can be used as a readymade purifying agent. A regular household bleach like Clorox contains 5.25% sodium Hypochlorite which purifies the water. Use a bleach without any scent so that it can be drunk without any repelling odors. Eight drops of bleach per gallon water are normally used and the water is set aside after stirring for thirty minutes before use. The process may cause debris to settle to the bottom of the pot. Filter them out using the tilt way like in the first step. Do not store this water for long as chlorine can turn harmful after long periods. Chlorine tablets are also easily available in the market and should be a part of your emergency kit.
Iodine can also be used to purify water. However, a very small quantity of iodine is used. You can add three drops of iodine to one liter of water. For muddy or cloudy water double the amount of iodine. Stir well and use only after 30 minutes when the debris has settled down. Filter the water out like in previous steps. Iodine tablets are also easily available.