From the concept of sustainability, combining aquaculture and hydroponics into one integrated system can be more economically and environmentally beneficial than operating them as separate enterprises because of reduction in land use and shared use of infrastructure, tools, and inputs. The integrated approach can also result in a more consistent supply and pricing of the products, which adds to its economic appeal. However, the efficient functioning of the integrated system requires an understanding of the complexity of combining various factors like the types of fish and vegetables grown, system design, and local climate.
This study used data from several sources including an experimental greenhouse setup and quotes from industry suppliers of aquaponics components, to examine profitability of a hypothetical 2000 sqft (40 ft by 50 ft) greenhouse setup. The data included the cost of land, greenhouse components, and other components of the aquaponics system; labor expenses; material and equipment prices, lettuce and tilapia selling prices, and other cost data. The system is a deep water culture system with three 8 ft by 32 ft grow beds producing 896 lettuce plants per system (2688 plants in total) at a harvesting rate of &fraq14;th of the lettuce from the system each week (672 plants weekly). Tilapia is produced in three fish tanks using advanced fingerlings, producing about 104 lbs of fish per tank (70 fish per tank) twice a year for a total of 210 fish in a year.
Preliminary analysis of profitability focused on estimating the net present value (NPV) and the internal rate of return (IRR) using a discount rate of 5% and a 10-year period. The analysis involved Monte Carlo simulation sensitivity analyses to examine the impacts of changes in key drivers on the overall profitability of the system. The results indicate that while aquaponics can be financially viable under certain conditions, facilities generally operate within very narrow margins. Infrastructure cost is the major constraint and would require minimizing capital expenditures. The scenario without real greenhouse cost produced positive NPVs and lower IRRs compared to the scenario that involved real costs associated with the greenhouse. The main drivers of profitability besides greenhouse costs were labor and the price of lettuce. Selecting high-value plants like basil may provide higher returns in combination with tilapia.