80% of the use of clean water by the community becomes wastewater which must be managed first before being discharged into surface water bodies not to cause disturbances to the water body environment, public health, and environmental aesthetics. This study examines the effectiveness of seven reactors for domestic wastewater treatment in reducing levels of BOD (BOD) and COD (COD). These reactors are the Moving Bed Biofilter Reactor (MBBR) with kaldness media, only MBBR, filtration pipes, the addition of papaya seed bio coagulant, Up-flow Anaerobic Sludge Blanket (UASB), pipes filled with soil, and a combination of filtration and Anaerobic Baffled Reactor (ABR). This research was conducted with a descriptive method of literature review. The results showed that the reactors, resp., reduced BOD levels by 83.3%; 78.9%; 15.75%; 93%; 36.9%; 76%; and 79%. They were able to reduce COD levels by 84.2%; 80.58%; 16.79%; 93%; 67.8%; 58%; and 68%. The addition of papaya seed bio coagulant is the most effective reactor to reduce BOD and COD because it contains tannin compounds that have effective clotting ability.