WATER QUALITY CHANGES AND GOLDFISH GROWTH (CARASSIUS AURATUS) IN MICROGREEN AQUAPONIC AND RECIRCULATING SYSTEMS

摘要

Goldfish (Carassius auratus) growth was studied comparatively in microgreen aquaponic (APS) and sump filter systems (SFS), and the effects of these two different filter systems on water quality parameters were investigated. Arugula (Eruca vesicaria) was used in APS and produced as microgreens. NH_3-N, NO_2-N, NO_3-N, PO_4 and NH_4 were measured at specific periods for 60 days. No statistical differences were found between both systems in terms of food conversion ratio (FCR), specific growth rate (SGR), survival and mean body weight of goldfish. In the beginning of the experiment, water pH level was around 8.5 while trend towards declining at the end of period. Nitrification process was successful in both systems, and declining pH towards from basic medium to approaching neutral levels made positive contribution to performance of nitrifying bacteria. Although there was a significant decrease in the level of NH_4, the level of NO_3-N increased continously after the 30~(th) day in APS. According to these results, arugula microgreens used mostly NH_4 instead of NO_3-N in higher pH level. Goldfish-arugula microgreen aquaponic system is similar with SFS in terms of keeping water quality in optimal conditions and any adverse effect on goldfish growth and welfare was not observed in both systems. Although in high pH, it was also seen that arugula seedlings can be produced efficiently as microgreens.