The symbiosis of fish farming and vegetable growing in a closed system, the so-called aquaponics, is on the rise in the Czech Republic. In order for business to be not only profitable, but also maximally ecological, it is necessary to balance a delicate balance in the system, which would suit both fish and plants. The researchers from the Brno University of Technology and the Institute of Global Change Research of the ASCR (CzechGlobe for short) have now come up with a solution. Together with Flenexa, they mapped the nutrient flow in the aquaponic farm, designed a model to predict the behaviour of the system and, according to the first laboratory tests, selected algae that should help make high-tech farming more efficient.