The cheapest and easiest way to disinfect water? Sunlight. Just leave a clear glass or plastic bottle out in the sun for six hours. SODIS, or solar water disinfection, is an age-old method touted by the World Health Organization for areas where access to clean water is limited. UV rays in the sunlight tear apart the microbes to make water safe. Drink up!
SODIS is quite effective, but scientists have found two hacks that make the technique even better. One problem is that the water may be cloudy from sediment, which can be fixed with a dash of salt. NPR’s Salt blog explains:
Pierce and his colleagues discovered that by adding a little table salt to this murky water, they could get the particles of clay to stick together and settle to the bottom, making the water clear enough to purify using the solar disinfection method. They also found that ...
