Device and method for holding water for accommodating and growing aquatic organisms

Device (1) for holding water for accommodation and growth of aquatic organisms, comprising a first chamber (2) for containing water with oxygen-depleted and a second chamber (3) for holding oxygen-rich water, and a porous substrate (4 ) comprising microorganisms and that is in contact with water with diminished oxygen and the oxygen-rich water, whereby the first chamber (2) is formed with at least part of the substrate (4) characterized in that a first circuit (5) having an inlet (6) and an outlet (7), which are in communication with the first chamber (2) is connected to at least a first chamber (2), and that there first step means (8) for the passage of water through the oxygen-depleted first circuit (5), and that the means (9) for conditioning the oxygen-depleted water are in contact correspondingly.