Twelve 0.2 ha ponds in West Java were fertilized weekly with four levels of chicken manure during a 149 day grow out experiment for Nile tilapia production. Laboratory leaching experiments for measuring dissolved inorganic nitrogen (DIN) release from chicken manure showed that nitrogen was released ammonia-N, which was rapidly lost from the manure and leveled off at about 6 mg NG4N/g dry weight chicken manure after 4-5 days. Allochthonous DIN input from both chicken manure fertilization and almost daily source-water additions ranged from 0.055 to 0.142 g N/m2 day-1. Source water contributed more nitrogen than manure in all but the highest fertilization treatment.