PURPOSE: An aerator for water purification is provided, which can keep seawater of an aquarium clean in a long term and maintain fish fresh. CONSTITUTION: An aerator for water purification comprises an inlet in which seawater is inhaled; a casing(100) in which an outlet in which the seawater is pumped is included; a motor(200) which is installed with the casing and is equipped so that a driving shaft can revolve; and an impeller which is installed on a driving shaft of the motor in the internal space of a casing. The impeller includes a plurality of veins which disperse oxygen into minute particles.
