Summary: | This paper presents the basic operations of an aquaponic prototype and preliminary results on the
growth of tench and lettuce. This prototype consisting in a water recirculating system made up of: fish
rearing tank with two outlet pipes, one of this connected to a biofilter, NFT hydroponics device and
sump; and the other one, to a raft hydroponic device draining to the same sump. Results showed a high
survival rate of tenchs (99,32%) and lettuces (98%), and finalization of vegetative cycle of lettuce with
commercial sizes, under the following assay conditions: tench stock densities between 0,68 kg/m3 and
1,19 kg/m3, with daily food rates between 0,88 y 1,23% of fishes biomass, a total system water volume
of 2,8 m3 and 1,26% of water reposition daily rate, and water variables parameters between 15 and 25ºC
temperature; 32 and 105 ppm of nitrate levels; and 8,25 and 7,3 pH values. Control of the above mentioned
parameters, plus oxygen levels in water, maintaining fish at low densities and without solids removal
devices, reached the optimum regulation system. |