The research was conducted for 56 days from February to March 2017. The aim of this research is to determine the number of water lettuce leaf meal fermented using cow rumen liquo (FWLL) in drets on growth and feed efficiency of Nilem (O.hasselti). This study used completely randomized design (CRD) with five treatments and three replications. 300 fingerlings of O..hasselti (initial weight 12 g )…