In the Koto Panjang Reservoir, the floating net caged fish culture produced organic meterials that negatively affects the water quality. A study aims to understand the concentration of BOD5 in the lacustrine and transition zones has been conducted from March to April 2016. There were 4 sampling sites, in the lacustrine 1 (L1), lacustrine 2 (L2), transition 1 (T1) and transition (T2). The vertic…