Final Report for FW05-312
Demonstration of recirculating system for the production of tilapia, leafy salad greens, kang kong and live bearing aquarium fish. The system is based on six 1,600 gallon tanks for tilapia in a green water culture system, with phytoplankton and "Bio-floc" for biological filtration. Water from these tanks is circulated through two filtration troughs in which kang kong and leafy salad greens are grown. These plants filter sediments, consume the nutrients from the fish waste, and provide an additional income stream for the system. Small aquarium fish are grown in the troughs to control mosquitoes, and sold to pet stores.
Tank-based recirculating aquaculture systems are used from tilapia production on many tropical islands where environmental constrants prevent prevent tilapia production in ponds. These sytems are resource intensive. One method to increase the profits from these systems is to incorporate additional enterprises into the system. This project brings additional income streams into the system by using an aquaponic component (leafy greens, and Kang kong) as its biological and chemical filtration system and by raising live bearing aquarium fish in these filters in addition to the Tilapia in the primary tanks.
Design, Build and Operate the Aquaculture System,
Design, Build and Operate Hydroponic Filter System.
Conduct a Field Day
Beyond Project Term, Document Fish and Plant Yields, and refine aquaponic methods of tropical lettuce production.
The project utilized the expertise of the farmer, a retired horticulturist, to imporve on the design of the hydro/aquaponics portion of previously demonstrated aquaponic systems on Guam. The system serves as a demonstration that will over time provide cost and return data that can be shared with our islands producers. The farmer and the ag professional consulted and worked together on every aspect of system design and installation. Where additional expertise was needed the ag. professional brought additional University faculty in to consult on system design.
A new low cost design for aquaponic tanks to serve as biological and chemical filters for recirculating aquaculture systems was developed and is being demonstrated for local producers to see. This design reduces the labor needed for lettuce production in these sytems though increased height and use of flats for growout in the system. Leafy greens are a very high demand crop on our islands so we anticipate producer adoption of this technology in conjunction with tilapia production.
Education and Outreach
While the project time frame is over, the professional and producer will continue with the project over the next year during this period we will:
Refine lettuce production in the tropics by growing in flats in this modified hydroponic/aquaponics trough system.
Hold Field Day/Workshop between March and May 2009.
Post Project Report/publication on six-month production cycle yields.
Education and Outreach Outcomes
On-going farmer-operated demonstration of an improved, low cost hydroponic/aquaponic system for tropical leafy greens production. Senior retired Horticulturist committed to improving and demonstrating this system.
On-going farmer-operated demonstration of small (9,600 gallon, 1,200 lb year) tilapia production unit using plants for filtration.
Site to be utilized by at least two Western SARE Ag Professional trainings in 2009.
When looking at duplicating the concepts utilized in this system, one change is recommended. Instead of a series of 6 small tanks the system would be more efficient if 2 or 3 larger (12-15 foot diameter) tanks were utilized. This would significantly reduce the fixed cost (tanks) for the tilapia production portion of the project.