The Effectiveness of Using Palm Kernel Shells as Growth Medium in a Flood and Drain Aquaponic System.

Abstract

An aquaponic system was developed with palm kernel shells as growth medium, to test the efficacy of palm kernel shells as biofilter and plant support medium in aquaponic systems. The system was developed based on specific parameters which was operated 6 hours daily for 45 days under controlled condition. Two culture tanks were considered and a total of 20 African catfish (Clarias gariepinus) of average initial weight of 148 g were stocked in each culture tank at 15kg/m³ density. Twelve days old healthy Amaranthus cruentus seedlings were transplanted to the grow bed after stocking of the fish. Water parameters such as Dissolved Oxygen (DO), pH, Total Dissolved Solid (TDS), Electrical Conductivity (EC) and Temperature were monitored every 48 hours; in addition, Ammonium Nitrogen, Nitrite and Nitrate were analyzed every two weeks. The range values of pH, DO, TDS, EC and temperature were 6.4-7.2, 4.1-6.75 mg/L, 126-201 ppm, 255-403 µS/cm and 28-33 ⁰C, respectively and the values were suitable for aquaponic organism (the fish, the plant and bacteria) when compared with W.H.O specification and optimal water quality for aquatic lives. The average gained in weight per fish was 109.83 g and average feed consumed was 188.26 throughout the experiment, the average Feed Conversion Ratio (FCR) was found to be 1.71 compared to that of control tank of 103.8 g, 187.43 g, and 1.80, respectively. The paired t-test was computed for fish conversion ratio for aquaponic and control systems to check the significant differences at significant level of 0.05and the results revealed a significant difference in favour of weight gained in aquaponic system as calculated value of t (t_cal) was 2.57 which is greater than tabulated value 2.01. The plant growth rates were 1.06cm/day and 1.01 cm/day in both aquaponic and traditional method.