Recirculating Production Pond Inflows to Increase Production and Reduce Effluents on Small-Scale Fish Farms

2005 Annual Report for OS04-018

Project Type: On-Farm Research
Funds awarded in 2004: $14,145.00
Projected End Date: 12/31/2006
Region: Southern
State: Alabama
Principal Investigator:
David Cline
Alabama Cooperative Extension System

Recirculating Production Pond Inflows to Increase Production and Reduce Effluents on Small-Scale Fish Farms


With guidance from University personnel and funding assistance from SARE, the cooperating farmer has had the opportunity to explore the economics of recirculating water through his multi-pond production system. Recycling this water along with integrating secondary non-fish crops has helped reduce the amount of potentially nutrient rich effluents leaving the farm and allowed the farmer to increase his productivity and efficiency.

Objectives/Performance Targets

The objectives for year two included:

Preparing the garden plots. Completing the harvest sorting and marketing of year 1 fish from raceways. Restocking the raceways with catfish. Preparing/repairing the aquaponic rafts and germinating seedlings. Feed fish and monitor their growth. Monitoring and maintaining water quality. Planting and maintaining aquaponic plant rafts. Harvest fish and plants and record the profits and losses associated with the project.


The cooperating farmer was able to accomplish the year two objectives, but not without some difficulty however. The farmer battled with illness and farm labor issues. Also the weather was not very cooperative.

Year one fish were harvested and the production levels were up. The aquaponic rafts were installed with the seedlings. The plants did very well for approximately two weeks and then appeared to suffer from lack of nutrients and overexpose to the sun. The second hurricane in as many years finished them off, so they did not contibute positively to the farmers bottom line. The additional vegetable plots were also devastated by the hurricane and resulted in only $1000 extra profit to the operation.

After consultation with some of the Auburn University horticulturists, it was determined that there were not adequate nutrients in the water to support the aquaponic plants. The decision was made to add a small amount of slow release fertilizer to each plant. This effort sustained the plants for a longer period of time, but this batch also demonstrated symptoms of overexposure to the sun. The rafts were white in color, and it was determined that the sun reflecting off this white surface was more than the plants could tolerate.

The fish produced in the raceways did very well in the recirculated water, and water quality never became an issue. These fish were marketed primarily through the farmers fee fishing operation and generated an slight increase in farm income.

The decision to hold the farmer field day/workshop was postponed until the spring when there would be more for the visitors to see.

Impacts and Contributions/Outcomes

The farmer reported production of an additional 1000lbs of tomatoes that resulted from the project. Most of the other vegetables were hit hard by the second hurricane. The second attempt to grow the aquaponic lettuce yeilded valuable information in terms of the nutrient requirement and sunlight tolerance of the plants. The farmer was disappointed with the results but was encouraged enough by the prospects to seek a method to concentrate fish wastes to improve the nutrient availability.

The cooperating farmer was so pleased with the results of the water recirculation efforts that he is constructing another set of raceways to further intensify his production, reduce labor requirements and concentrate the fish wastes to grow more plants.

Many farmers and patrons visiting the farm commented on the integration with the plants and considered it a valuable investment that they will consider for their farm.