PROBLEM TO BE SOLVED: To generate fine bubbles efficiently in liquid, to thereby activate aquatic organisms by heightening water oxygen concentration, in the case where the liquid is water in a cultivation water tank, and also to activate micro-organisms for filtering an ammonia component excreted from aquatic organisms.SOLUTION: An air diffusion pipe is arranged in a water tank, and bubbles are generated in water in a cultivation water tank, and bubbles are agitated together with water by a submersible pump, to thereby generate fine bubbles. Fine bubbles heighten a water oxygen concentration, activate aquatic organisms, and further activate micro-organism for nitrifying ammonia. Further, the fine bubbles adheres to excreta from aquaculture organisms or to a residue of a bait to float on a cultivation water surface, to thereby urge discharge thereof from an overflow pipe.SELECTED DRAWING: Figure 1【課題】 液体中に微細気泡を効率よく発生する。液体が養殖水槽の水の場合、水中酸素濃度を高め、水生生物の活性化をはかると共に、水生生物の排泄するアンモニア成分のろ過を行う微生物の活性化もはかる。【解決手段】 水槽内に散気管を配置し、養殖水槽内の水中に気泡を発生させ、その気泡を水中ポンプで水と攪拌することにより微細気泡を発生する。微細気泡は水中酸素濃度を高め、水生生物の活性化をはかり、アンモニアを硝化する微生物も活性化する。更に養殖生物の排泄物や餌の残滓に付着して養殖水面に浮かせ、オーバーフローパイプから排出させる。【選択図】図１
