In our greenhouse at the Berlin-Friedrichshagen site, fish and vegetables thrive under one roof. ASTAF-PRO (Aquaponic System for emission-free Tomato and Fish Production) consists of aquaculture and hydroponics circuits, together called aquaponics. A patented system regulates fluid flows between the two parts of the system. This ensures ideal growth conditions for both the fish and the plants, independently of each other. This way, the resources deployed, such as nutrients, water, heat and electricity, are used twice. The tomatoes use the nutrient-rich water from the fish tanks and the carbon dioxide (CO2) respired by the fish to grow. Cold traps capture the water vapour emitted by the plants into the air. This clean water is then added to the aquaculture circuit as required. Some of the operating energy is generated on-site by a photovoltaic plant.