GROWING OF GREEN CORAL LETTUCE AND RED HYBRID TILAPIA IN COMPACT AQUAPONIC PROTOTYPE AT DIFFERENT RECIRCULATION RATES

Abstract

In this work, a compact-size aquaponics prototype was designed and fabricated. One of the current challenges in compact aquaponics systems is optimizing the balance between fish waste production and plant nutrient uptake. The objective of the work is to assess the impact of different pump recirculation rates on the crops cultivation at such compact aquaponics unit. Main components included a 50 litres fish tank, a filter unit that combines the mechanical filter and biological filter counterparts, and nutrient film technique (NFT) grower. Production of food was carried out for 10 weeks at two different recirculation rates i.e. at 50 L/hr and 75L/hr. According to the data attained, the specific growth rate (SGR) was around 5.4-5.7% with a food conversion ratio (FCR) of about 1.8-2. Moreover, the fish survival rate was 80%, and plant growth yield is about 1.5-2 cm/week. Although the level of ammonia was slightly off the acceptable limit, no yellowish colour on the leaves of the green coral lettuce was observed. The data attained signify the successful operation of compact-size aquaponics for the production of organic leafy plants and freshwater aquaculture.