Techniques for drinking water shortages or emergencies
Domestic water treatment - Devices and good practices

Filtering the water is an important first step. If carried out correctly, it will improve the effectiveness of all the methods presented in this section.

Filtering muddy or dirty-looking water through a piece of thin, clean cotton cloth often removes some of the suspended solids and insect larvae contained in the water.

Cotton is the most suitable fabric. The fabric doesn't have to be transparent, but it shouldn't be too thick either, as it takes a long time to filter the water. Washing the cloth between each use will make filtering more efficient.