Pour water into any food container. The main thing that it was not iron. To pour need not to the brim. In capacity needs to go hand.
Put a bowl of water in the freezer.
Freezing should be gradual. After some time, the first frozen part of the water need to pull out and throw away. It froze contaminants.
Again to put water in the freezer. But that water is not frozen completely. To pull the water. To drain the water that is not frozen after all the bulk of the water is frozen.
The remaining ice will be the most healing part of water. No impurities, no harmful substances.
Defrost water gradually, at room temperature, away from heaters, frozen water in another way nothing to do with medicinal properties has.