PROBLEM TO BE SOLVED: To address such a problem that a lage-type culturing water tank requires a large installation area, the weight thereof including water is increased, and a high-strength material is also required, thus increasing the cost and complicating the handling.SOLUTION: A water tank apparatus is configured by superposing water tanks in a plurality of stages. A polystyrene foam made by an extrusion method is used for the bottom part and side wall parts of the water tank, and a polyurea resin is applied to the surface of the polystyrene foam made by the extrusion method, thus providing a light-weight and high-strength water tank. Thereby, the water tanks can be superposed into two stages without using an especially high-strength frame member or the like.COPYRIGHT: (C)2014,JPO&INPIT【課題】 養殖用水槽は大形になると設置面積も、水を含めた重量も大きくなり、強度の高い材料を資料する必要も有るため、コストも高く、取り扱いも大変であった。【解決手段】複数段重ねて構成する水槽において、水槽の底部と側壁部に押出法ポリスチレンフォームを用い、前期押出法ポリスチレンフォームの表面をポリウレア樹脂でコーティングする事により、軽量で強度の高い水槽を実現する。これにより、特に強度の高い枠部材等を使用しなくても水槽を2段に重ねる事ができる。【選択図】図1
