Co-production and biomass yield of amaranthus (Amaranthus hybridus) and tilapia (Oreochromis niloticus) in gravel-based substrate filter aquaponic

Abstract

Purpose Aquaponics combine aquaculture with crop production in a mutual system. In this experiment, the growth of Amaranthus in aquaponics with tilapia fish was investigated. Methods 500-liter water tanks containing tilapia fish at four initial stocking densities of 100, 150, 200, and 250 fish/m 3 were used in triplicates, with a view to evaluate vegetable yields as influenced by fish biomass to water ratio. 1 g of Amaranthus seeds were sown in a 1 m 2 planting trough, which contained gravel with a top layer of sandy soil. The pots were flooded with water from fish holdings by an aquarium pump. Results The germination rate of Amaranthus was not significantly different across the experimental setup (P > 0.05). The growth rate of Amaranthus was significantly higher with increasing fish density (P < 0.05). The average lowest and highest of shoots dry biomass yield recorded were 0.36 and 1.95 g/plant at 8 weeks after of sowing, and this corresponds to fish stocking densities of 100 and 250 fish/m 3 , respectively. A high positive correlation was found between the shoot dry biomass of Amaranthus and fish stocking density. The survival of tilapia fingerlings was not significant different, while the production levels were 5.62, 4.77, 4.57, and 4.00 kg/m 2 in 100, 150, 200, and 250 fish/m 3. Conclusions The growth of Amaranthus in this experiment demonstrated that the plant could effectively utilize the nitrogenous waste from fish tanks for biomass production, even at a higher concentration, while considerations for moderate fish density are only for fish health.

Performance of Nile Tilapia and vegetables Grown in Different Aquaponic Volumes

“…Increasing the volume of the fish production tanks from 500 to 1000 L while maintaining the fish density (12 fish/m 3 -4 kg/m 3 ) and the volume of the vegetable growing bed (500 L) did not improve the performance of the fish, which was possibly due to the maintenance of the water quality and of the fish stocking density. The effect of Nile tilapia density in gravel aquaponic system on performance was demonstrated by Babatunde et al (2019), who found a decrease in final weight (57.5 to 42.0 g), weight gain (43.2 to 34.0 g) and daily weight gain (1.0 to 0.79 g/day) as density was increased from 100 fish/m 3 (5.7 kg/m 3 ) to 250 fish/m 3 (10.0 kg/m 3 ). The performance results obtained in the present study are adequate, considering values obtained with Nile tilapia in net-tanks (Moraes et al, 2009) (biomass gain: 0.476 kg; feed conversion: 1.59), in fish ponds (Assano et al, 2011) (daily weight gain: 2.37 g/day; feed conversion: 1.3) and in aquaponics with biofloc technology (BFT) (Lima et al, 2015) (daily weight gain: 2.16 to 2.36 g/day; feed conversion: 1.38 to 1.62).…”

“…Good performance results have been obtained for vegetables and fish, such as tilapia, in gravel aquaponic systems at different stocking densities (Babatunde et al, 2019), and better biomass gain and yield results were achieved as compared with the NFT and raft systems (Lennard and Leonard, 2006).…”

Effectiveness of Filter Media Compositions on Water Quality, Growth and Survival Rate of Tilapia (Oreochromis niloticus) Cultured in Recirculation System

“…Tanjung et al (2019) reported that the best pH for tilapia was 7.0-7.4. The pH values for each treatment in this study were also suitable for the nitrification process (Trang et al, 2017;Babatunde et al, 2019). Wambua et al (2018) stated that the pH value of water is directly proportional to the temperature and the toxicity level of ammonia in the water.…”

Automated, technified and traditional aquaponic systems

“…Ingeniería Solidaria Table 5 shows the most commonly used species combinations together with the type of hydroponic system, reported yields and fish-plant ratios recommended by authors. Water flow is generally continuous, although flow rate varies depending on the specific dimensions of each system [48], as feed consumption and waste production may change depending on these.…”