For how long we should keep water in sun for charging? Can we keep the glass bottles outside at night so the water can get charged from early morning itself?
It is always best to sun charge the water for 5-6 hours before consumption.
It is best to use a wide mouthed earthen pot covered with a muslin cloth to sun charge the water. The earthen pot is porous and allows the goodness of the earth element to also enter the water. However, if earthen pot is unavailable, the next best option is a glass container with a wide mouth. If neither of these are available, you may use a steel vessel.