hard water

Water containing high concentrations of calcium and magnesium salts, often found in areas with limestone substrate.

Referencia

Coad, Brian & D.E. McAllister. 2007. "Dictionary of Ichtyology". Brian W. Coad. Retrieved on June 21, 2014, from:http://www.briancoad.com/Dictionary/Complete%20Dictionary.htm - (ffm06223)