GROWTH PERFORMANCE OF GIANT FRESHWATER PRAWN AND VEGETABLES (CHINESE CABBAGE AND LONG BEAN) IN AQUAPONICS WITH AND WITHOUT GRAVEL AS MEDIA FILTERS

This paper presents the growth performance of giant freshwater prawn (Macrobranchium rosenbergii), chinese cabbage (Brassica rapa) and lettuce (Vigna unguiculata) in aquaponic systems with and without gravel as media filter. The study was conducted in 60 days using glass aquarium (150 litres). The aquaponic system was designed by following the 'one-pump rule' where the culture water was lifted by a 40 watt submersible pump to the highest portion of the system before its flow to the bio-filtration tank, allowing the flow of the water by gravity along the plant tanks (PVC pipe with diameter 100 mm and 80 cm long) and finally returning back to the prawn-holding tank (glass aquarium with size of 92 cm X 46 cm X 46 cm).. Results from the t-test analyses showed that there were significantly differences (p<0.05) of V. unguiculata and nitrate concentration in the aquaponic system with and without gravel. The growth performance of V. unguiculata and NO₃-N concentrations were recorded higher in the tank with gravel media. The other parameters, such as DO, pH, temperature, ammonia, nitrite, phosphate and growth performances of M. rosenbergii and B. rapa were no significantly differences (P<0.05). These results showed that the gravel media did not affect water quality and the growth performance of prawn and cabbage. This paper suggested that the filter media of gravel is the best and feasible integrated aquaponic system for giant freshwater prawn, Chinese cabbage and lettuce.