Perubahan Ammonia (Nh3-N), Nitrit (No2-N) Dan Nitrat (No3-N) Pada Media Pemeliharaan Ikan Nila Merah (Oreochromis Sp.) Di Dalam Sistem Resirkulasi

Abstract

High rearing density of fish in an intensive culture system require high amount of feed which may result in the accumulation of organic materials in the water to a higher level. The accumulation of organic materials can be toxic for fish, generate mineralization of nutrient from organic materials and cause high oxygen expenditure. Recirculation system is an aquaculture system which aimed to maintain water quality at an appropriate level for fish to survive and grow, Theammonia concentration in recirculation system with biofilter tended to decrease sharply while there was only a slightly decrease in that without biofilter. Conversion efficacy of ammonia nitrogen (NH3-N) and nitrite nitrogen (NO2-N) of biofilter compiled with aeration system was 46.20% and 30.68%, while in an unaerated system was 39.31% and 8.53%, respectively. The use of aquatic plant was found to be an effective way to reduce nitrate nitrogen (NO3-N). A higher conversion efficacy of nitrate (50.15%) in the tank containing aquatic plant was observed by using aeration before biofilter.