PROBLEM TO BE SOLVED: To allow control of cultivation conditions and achieve easy exchange of crops with excellent water quality purification properties.SOLUTION: The media bed for a water culture portion of a system according to one embodiment of the present invention circulates water within the system having an aquaculture portion and a water culture portion, aquatic organisms and/or their eggs are cultivated in the aquaculture portion and agricultural products are cultivated in the water culture portion. The media bed comprises: a purification tank for purifying water supplied from the aquaculture portion； a solution intermittent device that discharges water to a second water level if the water has reached a first water level in the vertical direction of water in the media bed； a cultivation portion configured sequentially of an absorption sheet, a root prevention water permeable sheet, and a culture medium from the lower side in the vertical direction. The first water level is set to be the position of the absorption sheet.SELECTED DRAWING: Figure 2【課題】栽培条件を制御でき、水質浄化性に優れ、農作物の容易な交換を実現する。【解決手段】本発明の一実施形態に係るメディアベッドは、水産養殖部と水耕栽培部とを有する系内で水を循環させて、前記水産養殖部で水棲生物及び／又は前記水棲生物の卵を養殖し、水耕栽培部で農産物を栽培するシステムの水耕栽培部用のメディアベッドであって、メディアベッドは、水産養殖部から供給された水を浄化する浄化槽と、メディアベッド内の水の鉛直方向の水位が第１の水位に達した場合に、第２の水位になるまで水を排出する溶液間歇装置と、鉛直方向下側から吸水シート、防根透水シート及び培地を含んで構成される栽培部と、を有し、第１の水位は、吸水シートの位置に設定されている。【選択図】図２
