The utility model discloses a phytoplankton who can quantitative control subsides volume subsides device, including sedimentation pipe, cock, the settler stopper of taking the scale, move liquid glass pipe, move the liquid hose, medical transfusion system flows speed adjusting festival ware, the waste liquid jar is constituteed. At the bottom of being conical hopper at the bottom of the settler, settler upper portion is cylindrical glass sedimentation pipe, is equipped with the cock at the bottom of the conical hopper, and sedimentation pipe top adds the settler stopper that there is a round hole at the lid middle part, move liquid glass pipe upper end from the settler beyond the great wall the round hole pass, that moves liquid glass pipe upper end and be equipped with that medical transfusion system flows speed adjusting festival ware moves the liquid hose connection, moves liquid glass pipe lower extreme and is connected with the filter screen, moves liquid hose end and moves liquid glass union coupling, move the liquid hose other end place with the waste liquid jar in. Simple structure can be quantitative, and convenient to use is nimble, even if it fails and also can not cause obvious influence to subsiding concentrated rate to get liquid midway, is suitable for the laboratory and carries out the concentration to the phytoplankton sample quick, accurately, convenient.