Optimization of Water Circulation Period for the Culture of Goldfish with Spinach in Aquaponic System

Experiment with varied water circulation periods having 4, 8, 12, and 24 hrs/day as T1, T2, T3 and T4, respectively in aquaponics, evaluated against a control (without aquaponics) revealed higher fish and plant growth in T3 and T4. The mean growth of fish varied significantly among treatments showing higher growth in T4 and control followed by T3, T2 and T1. Survival rate was 100% in all the treatments as well as control. Percentage weight gain, SGR (% day-1) also showed the similar trend as that of growth showing T4 as better treatment immediately followed by T3 then T2 and T1. The system maintained favourable water quality throughout the experiment. The growth in T3 and T4 did not vary significantly and was higher than the T1, T2 and control. Also percentage length gain at the end of the trial was maximum in T3 and T4. The Chl (a+b) content in the control was higher than all the treatments whereas, T4 showed the maximum concentration among treatments followed by T3, T2 and then T1. Comparison of all the growth attributes and water quality parameters indicated that water circulation can be reduced to 12 hrs/day for economically effective aquaponics and can be considered as optimum water circulation period for goldfish production in aquaponic system.