question: How long should the plastic bottles filled with water be exposed to sunlight during Solar water disinfection ?
answer: a minimum of six hours to two days during fully overcast conditions
turker_answer: Plastic bottles filled with water should be exposed to sunlight during Solar water disinfection for a minimum of six hours to two days during fully overcast conditions .
rule-based: The plastic bottles filled with water should be exposed to sunlight during Solar water disinfection a minimum of six hours to two days during fully overcast conditions .