Outlet tank (4) for a fish cage (1) equipped with at least one outlet hose (91, 99) extending from the outlet tank (4) to a surface (17), characterized in that the tank ( 4) The outlet includes: - a cylinder-shaped housing (41) which is provided, in its upper part (410), with a mounting collar (43) arranged to join a bottom part (179) of the cage (1) for fish, and which is provided, in its lower part (419), with a through opening (413)； - a cylinder-shaped outlet channel (45) which, in one part, is housed in the housing (41), the outlet channel (45) being provided, in its upper part (450), with an element (453 , 453 ') of filtrate covering a cross section of the outlet channel (45)； - an elongated annular space (46) between the housing (41) and the outlet channel (45)； - an inclined mesh (47) covering the entire annular space (46), placing a lower part (479) of the inclined mesh (47) just below the opening (413) of the housing (41), in which the opening (413) leads to a first pipe receptacle (415) arranged to be sealed connected to a first outlet hose (91)； - an inclined bottom plate (49) placed in the annular space (46) below the inclined mesh (47) and sealing all the annular space (46) against the housing (41) and the outlet channel (45) ； and - a bottom through opening (493) in a lower part (499) of the bottom plate (49).Depósito (4) de salida para una jaula (1) para peces dotado de al menos una manguera (91, 99) de salida que se extiende desde el depósito (4) de salida hasta una superficie (17), caracterizado porque el depósito (4) de salida incluye: - un alojamiento (41) con forma de cilindro que está dotado, en su parte (410) superior, de un collar (43) de montaje dispuesto para unirse a una parte (179) de fondo de la jaula (1) para peces, y que está dotado, en su parte (419) inferior, de una abertura (413) pasante； - un canal (45) de salida con forma de cilindro que, en una parte, está alojado en el alojamiento (41), estando el canal (45) de salida dotado, en
