Sail River is one of the Siak watersheds that have been polluted due to high levels of TSS, TDS, and turbidity. This study aims to determine the level of reduction in TSS, TDS and turbidity levels by using different bioijuk densities. This research was conducted in March-April 2019. The method used was a completely randomized design (CRD), which was used as treatment, was bioijuk density. P…