DECOUPLED AQUAPONICS FOR IN SITU NUTRIENT MITIGATION FROM RAS:

Huy Tran
Apopka Aquaponics Farms, Apopka, FL. USA 32803, Anglerhuy@yahoo.com

Abstract - Define and show components of a decoupled aquaponic system. The goal of which is to provide a "closed loop" nutrient cycle for the cultured aquatic and plant species.     

Introduction - Intensive hydroponic plant production has been demonstrated to be an economically viable alternative to extensive traditional agriculture for many highly prized food crops.   Likewise intensive recirculating aquaculture has provided high grade fish to markets around the globe for decades and has resulted in decreased pressure on natural fisheries and increased recruitment and general health of natural populations that were at one time severely overfished and unsustainable.  Both of these modern agricultural methods still have shortcomings with respect to the management of excess nutrients.  Traditionally exhausted hydroponic nutrient solutions (no longer able to support the growth of macrophyte but still high in nitrogen and phosphorus) were discharged to sanitary sewers or natural waterways as were the nutrient laden wastewaters from intensive aquaculture operations.  These effluents result in added nutrient loading in natural waterways and have been responsible for algae and bacterial blooms, fish kills, and the eutrophication of lakes, streams and rivers.  

Decoupled aquaponic is an alternative to these practices allowing the farmer to "close the nutrient loop", but not compromising each system, and avoid or minimize wastewater discharge to the environment.  In this scheme, aquaculture wastewater, high in phosphorus and nitrogen, is pumped to the hydroponic system, which act as "sinks" for these nutrients.   By incorporating the clear supernatant, all solids and associated water from RAS, N and P into the plant biomass of the hydroponic production, these nutrients are no longer available as potential pollutants.  

Aquaponics, coupled and decoupled, technology are improving every day and our industry should be at the forefront of development both as educators and stewards of the environment.