Wells, rivers, lakes and oceans all have different types and levels of contaminants. These contaminants, other than living organisms or turbidity are in the form of dissolved solids. The total dissolved solids are all the salts or minerals contained in the water source. These salts and minerals can be broken down into ions. The positively charged ions are called Cations and the negatively charged ions are called Anions. The hardness ions are primarily calcium, magnesium and iron which are Cations. The hardness in water causes scale to form inside pots and pans, pipes, water heaters or boilers.