Nannochloropsis sp. is phytoplankton which is usually used as a natural food source for zooplankton, such as Rotifer (Brachionus plicatilis). Nutrition and water quality in the culture media greatly influence the density of Nannochloropsis sp. This research aims to obtain the best dose of Liquid Organic Fertilizer (LOF) from catfish waste (Pangasianodon hypohthalmus) on the density level of Nan…