Evaluation of different hydroponic media for mint (Mentha arvensis) with common carp (Cyprinus carpio) juveniles in an aquaponic system

Three hydroponic media crushed stones (T1), river stones (T2), and floating raft (T3) were compared in an aquaponic system with common carp (Cyprinus carpio) and mint (Mentha arvensis). Fish effluents were used as plant nutrients while plants filtered water by stripping off the nutrients before returning to the fish tank. Fish growth, plant growth, and water quality parameters were used to evaluate the suitability of three different media. Growth performance of common carp and mint followed the relationship of crushed stones > floating raft > river stones with significant difference observed among all treatments. Total ammonia nitrogen (TAN) removal varied significantly among different treatments. The maximum TAN removal was observed in T1 (77.13%) followed by T3 (69.65%), and the minimum removal was observed in T2 (48.82%). Nitrate removal varied significantly among different treatments. The highest removal was observed in T1 (82.95%) followed by T3 (68.04%) and T2 (59.51%). Removal of phosphate was significantly lower in T2 (50.12%) when compared to T1 (67.85%) and T3 (70.71%). Biofilter performance (g m−3 day−1) of T2 (4.80) was significantly lower compared to T1 (7.13) and T3 (7.37). Crushed stone and floating raft were significantly efficient when compared to river stone medium in terms of nutrient removal and water quality maintenance for the fish culture. Considering all growth parameters, crushed stone media proved to be better when compared to other two media. Thus, medium selection could be a considerable factor when designing an aquaponic system.