Abstract: Provided is a water quality management apparatus for an aquaculture pond, the apparatus having a storage unit for storing water quality-related measured values measured at appropriate time intervals by external sensors set in the aquaculture pond, an assessment unit for calculating a predicted future value on the basis of fluctuations in the measured values and determining the time when the predicted value will exceed a reference value that indicates deterioration of water quality, and a display unit for displaying the time when the reference value will be exceeded. Said time is the time when exchange of pond water will be necessary.