Can You Purify Water from a Lake Without Tablets?

Boiling Method

Boiling water is the simplest and most effective method to purify it. To do this, fill a pot with lake water and bring it to a rolling boil for 1-3 minutes at an elevation of 0-6,562 feet (0-2,000 meters). At higher elevations, the boiling point is lower, so adjust the boiling time accordingly. For example, at 8,200 feet (2,500 meters), boil for 3-5 minutes.

Sand Filtration Method

A sand filtration system can remove particulate matter, bacteria, and parasites from lake water. To build a simple sand filter, create a container with a layer of coarse gravel, followed by a layer of sand, and finally a layer of activated charcoal. Attach a spigot at the bottom of the container and pour lake water through the filter. The filtered water can be collected at the spigot.

Solar Still Method

A solar still is a simple device that uses the sun’s heat to evaporate water and condense it into a collection vessel. To build a solar still, dig a shallow hole and place a container in the center. Fill the container with lake water and weigh down a clear plastic sheet with rocks. Place a second container under the plastic sheet to collect the condensed water. As the sun heats the water, it will evaporate and condense on the underside of the plastic sheet, dripping into the collection vessel.