RESULTS AND DISCUSSION
Carp breeding and water purification by gel beads The water quality profiles from aquariums for carp breeding using different gel beads in the water circulation filter were compared. As shown in Fig. la, the COD increase in the aquarium with alginate gel beads packed in the filter vessel was slightly suppressed during the 2- week carp breeding period compared with that of the water quality of the control experiment (no gel beads).