Which element is used to remove the permanent hardness of water? A) Washing soda B) Calcium C) Magnesium D) Chlorine Related MCQs: The permanent hardness of water due to sulphates of metals can be removed by the use of? Permanent hardness of water can be removed by adding? Who constructed five canals to remove scarcity of water? Less than one percent of Earth’s water is fresh water but the oceans contain ….. percent of the earth’s water?