The puspose of this research was to study the symbiotic system of a complex microorganisms contained in Starbact® as a decomposer agent with the addition of photosynthetic microoalgae Chlorella sp. as an oxygen producer in reducing organic loads of sago milling effluent. The experimental design was Completely Randomized Design (CRD) with 5 treatments and 3 replications. The treatments were con…