Dosage was one of the most important parameters that been considered to determine the optimum condition for
the performance of coagulant in coagulation and flocculation. Basically, insufficient dosage or overdosing would
result in the poor performance in flocculation (Hassan, Tan, & Noor, 2009). Therefore, it was crucial to determine
the optimum dosage in order to minimize the dosing cost and obtain the optimum performance in treatment. The
optimum dosage of coagulant is defined as a value above which there is no significant increase in removal efficiency
with further addition of the coagulant (Zainol, Aziz, Yusoff, & Umar, 2011).