ABSTRACT: Studies have shown that tannin, a natural substance extracted from the bark and leaves of trees such as black wattle, is promising as a flocculant for water treatment, since it can be used in wide pH ranges, i.e., without the need for additional chemicals to stabilize the pH of the water. Furthermore, its use has proven efficient in removing turbidity and toxic metals. This work aims to study the influence of physical parameters, turbidity and pH on the efficiency of tannin as a natural coagulant through case studies and data found in the literature with their respective concentrations and data’s studies to verify the behavior of these parameters. It was observed that pH between 7 and 8 has a great effectiveness in removing turbidity from water for optimum concentrations of tannin as coagulant from 1.82 mg/L up to 3 mg/L, for a Turbidity up to 139 NTU.