Investigation of goldfish growth and water quality changes in aquaponic and recircularing systems

Aquaponics has recently been most prevalent as a viable form of alternative agriculture. In many countries and lately in Turkey these systems have been used in a modern way with the help of developing technology. The present study has been carried out in the light of the popularity and practicability of this system. In this study, the growth of goldfish (Carassius auratus) was studied comparatively in aquaponic (APS) and sump filter systems (SFS) and the effects of these two different filter systems on water parameters were investigated. Arugula (Eruca vesicaria) was used in APS and produced as microgreens. The effect of the plant on water quality was compared with SFS and the productivity of filtration systems was examined. Goldfish with a mean live weight of 1,76±0,03gr were stocked in six aquariums each with fifteen goldfish. Arugula seeds were germinated by being kept in water for three days. These seeds were then planted by sprinkling over aquaponic beds each with about two hundred seeds. In the experiment that lasted sixty days, NH3-N, NO2-N, NO3-N, PO4, and some anion and cation values were measured at specific periods. At the end of the experiment, mean live weights of goldfish reached 3,11±0,100 gr in APS, and their live weights reached 3,07±0,103 gr in SFS. Their specific growth rates and food conversion ratio in APS and SFS were calculated to be 0,94±0,024 - 0,93±0,014 and 2,04±0,062 - 2,01±0,056 respectively. The survival rates in both groups were recorded 100%. During the experiment, nothing bad or negative that could affect the health and welfare of goldfish experienced in terms of water quality in both APS and SFS. The pH value tended to decrease in both systems towards the end of the experiment while the pH values at the beginning were at the level of 8,5. The findings showed that the nitrification process had been successfully carried out in APS and SFS. Also, it was revealed that the performance of SFS in nitrification process was relatively better than APS. In the study, the NH4 values was set 0,0054 NH4 mg/lt in APS and 0,0019 NH4 mg/lt in SFS on the 30th day. At the end of the experiment, on the 60th day, it was recorded 0,0033 NH4 mg/lt in APS, 0,0022 NH4 mg/lt in SFS. There was a significant decrease, in NH4 values in APS, however in NO3-N values there was a steady increase since the 30th day of the study. According to these results, arugula sprouts used mostly NH4 instead of NO3-N in high pH medium. The microgreens length of arugula reached 3,78 cm in 20 days. A slowdown growth rates of arugula sprouts was observed due to the high pH in the following days. In general, it is clear in the research that goldfish and arugula which are the subject of the thesis, are similar to SFS in keeping water quality in optimal conditions in APS and there is no negative effect on the growth and survival rate of the goldfish. It is also clear in the present study that it is possible to grow arugula as microgreens.