Chitosan, ferric sulfate, and alum were each tested at different concentrations (50, 75, 100, 125, and 150 mg/L). The flocculants were added to algae cultures (pH 7.2) at the onset of stationary phase. A standard jar test procedure was applied to assess coagulation performance, which comprised 1 min fast mixing at 350 rpm then 10 min slow mixing at 50 rpm, as adapted from Ma and Liu (2002). Afterwards, samples were allowed to settle quiescently for 10 min. A control algae sample without any added flocculant was also tested. The turbidity of each sample was measured with a Hach 2100N Turbidimeter. The zeta potential of the samples was measured by a Zeta Meter System 3.0+(Zeta-Meter Inc.) following the procedures described in Henderson et al. (2008).