This study was conducted to establish the pilot-scaled ponds that farming managements was operated in accordance with the written standards for organic aquaculture. The purpose was to build a quasi-organic model for farming tilapia, so as to help farmers understand the operations of organic aquaculture. The stocking density was 0.23 kg/m2 in the organic pond, while that in the regular pond was 0.45 kg/m2. The results of 12-week farming trial showed that the growth performance and feed utilization of organic fish were better than that of the regular one as long as well established operation. Moreover, the plastic sacks were introduced into the water column in organic ponds for bio-films and periphyton to grow upon and upon which fish could graze. In this way, the decrease of organic feed input and reduction of production costs could be achieved under the restrictions from organic regulations.
Keywords: organic aquaculture, tilapia, organic feed, periphyton.