2.1. Aquaponic system
Aquaponic is a special form of recirculating
aquaculture systems (RAS), namely a polyculture
consisting of fish tanks (aquaculture) and plants
148 A. Graber and R. Junge / Desalination 246 (2009) 147–156that are cultivated in the same water circle (hydroponic) [3–5]. The primary goal of aquaponic is to
reuse the nutrients released by fishes to grow crop
plants. Most systems separate fish faeces as
quickly as possible to reduce the BOD load in
the RAS, to enhance nitrification performance
and to reduce clogging of plant roots, which
could lead to loss of crop productivity.
Our aquaponic system established in Waedenswil, Zurich, was a new concept using ligh