EFFECT OF TANK GEOMETRIC SHAPE RATIO ON PRODUCTIVITY OF RECIRCULATING AQUACULTURAL SYSTEM

The main aim of this work is to study the effect of tank diameter depth ratio on the water quality and productivity of recirculating aquacultural system to reach the optimum tank diameter: water depth ratio. The obtained results indicated that the mean weight of fish increased from 18 to 148, 18 to 136 and 18 to 114 g after 14 weeks with the diameter depth ratios 4, 6.4 and 8, respectively. The average weight gain of fish increased from 2 to 21, 8 to 13 and 3 to 6 g after 14 weeks with the diameter depth ratios 4, 6.4 and 3, respectively. The specific growth rate ranged from 0.99 to 6.00, 0.39 to 5.25 and 0.17 to 5.10 % day^-1 at 4, 6.4 and 8 diameter depth ratio. The feed conversion rate ranged from 0.68 to 3.53, 0.88 to 10.91 and 0.93 to 18.51 kg feed/kg fish at 4, 6.4 and 8 diameter depth ratio. The feed efficiency ranged from 0.28 to 1.46, 0.11 to 1.13 and 0.05 to 1.39 at 4, 6.4 and 8 diameter depth ratio. The mean daily mortality rates were 0.048, 0.058 and 0.064 % at 4, 6.4 and 8 diameter depth ratio, respectively.