According to the European Parliamentary Research Service (EPRS), aquaponics is one of the ten technologies that could change our lives. Since aquaponics uses a recirculating system, the amount of water used is significantly reduced compared to traditional methods of agriculture and aquaculture, and wastewater (containing nutrients) is not discharged into the environment but utilized for growing plants in the system. However, aquaponics can be profitable only if the species grown in the system have high commercial value. There is continuing research to test several species for growing in specific types of aquaponic systems. In previous experiments, we successfully produced Nile tilapia ( Oreochromis niloticus) together with several plant species.
The experiment aimed to determine the most suitable type of aquaponic system for producing Asian seabass (Lates calcarifer) and cherry tomato ( Solanum lycopersicum), which are considered more profitable compared to other species commonly grown in aquaponic systems. Two types of aquaponic systems were compared: floating and media-based (hydrostones ) systems, both made of fiberglass tanks and equipped with sedimentation and biofiltration tanks. The dimensions of the fish tanks were 90 x 60 x 50 cm, and the plant tanks were 90 x 60 x 30 cm. Four replicate tanks were used for each type of aquaponic system.
Asian seabass, with an initial body weight of 0.5 g, were fed a commercial feed at 5% of body weight, later reduced to 3% of body weight. Growth and survival rates of Asian seabass were found to be similar in both aquaponic systems, with an average body weight of 271 g and an average survival rate of 82% after 12 months.
Cherry tomatoes were grown in two batches over 12 months. In the first batch, each plant tank contained one tomato plant, while in the second batch, each plant tank contained two tomato plants. The number of cherry tomato fruits was higher in the media-based system (306 fruits per plant) compared to the floating system (174 fruits per plant).
While temperature, dissolved oxygen, and pH did not differ significantly between the two systems, ammonia levels were higher in the floating system, indicating less efficient nitrification and production of nitrates to support tomato fruit production.
In conclusion, the study suggests that the media-based aquaponic system is more suitable for the production of cherry tomato fruits, alongside Asian seabass. This system demonstrated higher fruit yields per plant compared to the floating system, likely due to better nutrient availability facilitated by efficient nitrification processes.