This study aimed to analyze the effect of adding shallot (Allium cepa) liquid into fish feed on the growth performance and profitability of farmed red tilapia (Oreochromis sp). Three different doses of 0.0% (treatment A), 2.5% (treatment B), and 5.0% (treatment C) of feed weight were used in this completely randomized design study done within 30 days. Test fish with an initial size of 2.11±0.03 g were reared in fiberglass tanks at a stocking density of 30 fish per tank and fed 4% of biomass per day. The parameters observed included specific growth rate (SGR), weight gain rate (WGR), survival rate (SR), feed conversion ratio (FCR), and benefit cost ratio (BCR). The results showed that shallot liquid addition to the fish feed significantly affected the growth, feed efficiency, and BCR. Liquid shallot at low doses produced high WGR and SGR values along with a more efficient FCR. In this study, the control treatment (treatment A, 0.0% shallot liquid) resulted in the most optimal performance, while the highest SR and BCR values were obtained in the control treatment. Polynomial regression optimization analysis indicated that the optimal dose ranges low, between 0.131 and 0.694%.
