Dynamics and fluctuations of ammonia, nitrite and nitrate in the utilization of tilapia cultivation waste in Aquaponics-NFT (nutrient film technique) based on biofloc

In an aquaponic system that integrates fish and plants, a recirculating aquaculture system (RAS) is used to circulate 90-99% water continuously. Fish waste is used for plant nutrition and reduces waste disposal in the environment. One of the functions of biofloc technology is to improve water quality. Several water quality parameters influence each other and do not stand alone. In the study of aquaponics, nutrient film technique (NFT) based on biofloc consisted of a fish pond tank (FPT), mechanical filter tank (MFT), biological filter tank (BFT), storage tank (ST), and hydroponic plant circuit (HPC). The results of the study show that the concentration of water quality parameters is always dynamic and fluctuates, namely: ammonia, from 0.4525 to 9.2625 mg L-1; nitrite, from 0.1050 to 0.2238 mg L-1; and nitrate, from 0.6226 to 9.7975 mg L-1). In general, the concentrations of nitrite and nitrate were still within the permissible threshold interval, except for the ammonia concentration, which is very dynamic and fluctuates in a wide interval. The application of biofloc technology (BT) in aquaponics has contributed to technology for improving water quality, increasing fish survival, and fish and plant production.