Study on the plant and fish production in the aquaponic system as affected by different hydraulic loading rates

Aquaponics is the combined culture of fish and plants in recirculating aquaculture systems, considered to be an innovative, eco-friendly and sustainable technology. The effect of the hydraulic loading rate (HLR) on the performance of fish and plants in the aquapoinc system was the main aim of this study. Four hydraulic loading rates were applied, 1.2, 1.8, 2.4 and 3.0 m day−1 under stocking density tilapia fish of 5 kg m−3 and lettuce population of 25 plant m−2 for a period of January to March, 2023. Water parameters, plant and fish parameters were determined. The most important results revealed that the highest plant nutrients removal was at HLR of 2.4 m day−1. The highest value of water parameters were found at the HLR of 2.4 m day−1. Root length increased with increasing HLR. Fresh and dry shoot and root weight values were higher at 2.4 m day−1 compared to other treatments under study. Meanwhile, fish growth parameter showed higher values at the HLR of 3.0 m day−1 compared to other treatments. The highest values of weight gain, feed growth rate, specific growth rate and feed conversion ratio were 81.72 g, 1.36 g day−1, 1.88% day−1 and 1.20 g feed g−1 fish, respectively, for all treatments under study.