ABSTRACT Water hyacinth (Eichhornia crassipes) can be used as fish feed and has a fairly high protein content ranging from 9.8-12.0%. This study aims to determine the effect of using fermented water hyacinth (Eichhornia crassipes) leaf flour in feed on the growth and feed efficiency of nilem fish (Osteochilus hasselti). This research was conducted for 56 days at the fish nutrition laborato…