Performance of floating and media-based aquaponic systems with two tank sizes for Nile tilapia and cherry tomato

This study compared floating and media-based aquaponic systems in two tank sizes with respect to water quality, Nile tilapia (Oreochromis niloticus) growth, and cherry tomato (Solanum lycopersicum) production. The experiment used small (100 L) and large (200 L) tanks stocked with 30 and 60 Nile tilapia per tank, respectively, from May to August 2023 at Sultan Qaboos University. Fish were monitored for weight gain (WG), feed conversion ratio (FCR), specific growth rate (SGR), and survival rate (SR). One cherry tomato plant was grown per plant tank, and flowers and fruits were counted monthly. Water quality (temperature, dissolved oxygen, pH, ammonia, nitrite, nitrate) was measured weekly. System type did not significantly affect WG, FCR, or SGR. Tank size had a significant effect on WG, with fish in small tanks growing more than those in large tanks, while FCR and SGR did not differ between tank sizes. Survival was high in all treatments (95–98.3 %). Media-based systems produced higher cherry tomato yields than floating systems. This difference was significant for total flower and fruit production over the June–August period, whereas tank size did not affect reproductive output. Water quality remained within acceptable ranges for Nile tilapia in all treatments. Nitrite concentrations were consistently lower in media-based systems than in floating systems, while ammonia and nitrate did not differ significantly between systems or tank sizes. Overall, both configurations supported good Nile tilapia performance, but media-based systems provided clear advantages for fruiting crop production in small-scale aquaponics.