Moringa oleifera (MO) Lam. seeds and MO powder waste (an available residue from oil-extracted MO cotyledon), available in the Ecuadorian coast region were investigated as natural coagulant-flocculant agents for drinking and wastewater treatment applications. The optimum particle size range of crushed moringa seeds without husk at a fixed dosage of 50 mg/L was evaluated during jar tests. Three water sources from the Metropolitan District of Quito (MDQ), Ecuador: Monjas and San Pedro Rivers (main rivers that crosses the district) and the effluent from a Pilot Water Resource Recovery Facility (PWRRF), were selected. When coagulation-flocculation process was applied as a sole process after the recollection of crude water, the statistical results from a Randomized Complete Block Design (RCBD) over the sources concluded that water quality was improved by 41.90-51.94%, 55.32-71.10%, and 74.42-87.73%, for chemical oxygen demand (COD), turbidity and E. Coli, respectively. In addition, the use of moringa powder waste and complete moringa seeds also proved suitable for COD, iron, and turbidity removal, where moringa powder was significantly apt for turbidity removal, and moringa treatments with husk, were significantly apt for iron reduction. The statistical differences from particle size range and dosage studies, as well as the results from the use of different moringa seed parts are thoroughly discussed in this work.