Aquaponic farms that decide to grow entirely indoors with no natural sunlight have a large list of lighting technologies to choose from. Over the last decade, research led by Dr. Jim Tidwell at Kentucky State University (KSU) has evaluated different lighting technologies for use in indoor aquaponic farms. Initial research conducted by Charlie Schultz and Luke Oliver on lettuce, basil, pak choi, and kale showed that LED lights were better than induction, fluorescent, and metal halides in term of total amount of plants grown and grams of plants produced per kWh. However, LED grow lights are expensive to purchase, with many costing $1,000 and higher per light. This represents an initial investment cost that is too high for many small-scale or limited resources farmers. 

To utilize the benefits of LED grow lights while making their use economical, researchers at KSU evaluated seven inexpensive LED lights that ranged in cost from $80-$364 per light for Bibb lettuce production (Table 1). Performance was compared to an expensive horticulture grow light (NeoSol DS; $1,400).  Results indicated that hat six of the seven LED lights could produce comparable amounts of lettuce to the NeoSol DS and that three of the seven lights were more efficient in converting electrical energy into plant biomass. 

To validate the results from our smaller replicated systems, researchers implemented an on-farm trial at FoodChain in Lexington, KY. FoodChain is a 501c3 non-profit, located in an urban food desert, which has an indoor aquaponics farm with 645 ft² of growing area. This research successfully demonstrated that inexpensive LED lights can produce lettuce in a quantity comparable to expensive LED lights.

Results from this trial informed FoodChain on the best lights for their system. FoodChain replaced all of the grow lights in their system based on results of this work. 

To give an example on the cost-savings achieved, it would require 40 NeoSol DS lights at a cost of $1,400 per light to cover the entire grow area at FoodChain. That’s a whopping $56,000 investment just for grow lights. For a small farm just starting up, that cost can be prohibitive to obtaining a reasonable return on investment or becoming operational at all.  However, this same farm equipped with $300, lightweight LED lights, could be covered for $12,000! That is a cost savings of over $44,000!!!

Applied research, like that conducted here, allows sustainable, indoor farming to be more economical and accessible to limited resource farmers. By reducing start-up and operational costs, aquaponics in urban environments starts to make more economical sense. This can expand the reach and application of aquaponics in urban centers and reduce the financial risk to small or limited resource farmers.  

The on-farm research was conducted by Janelle Hager, Andrew Lohman, Chris Ward, and Dr. Jim Tidwell.