DEMONSTRATION OF A SMALL-SCALE DECOUPLED AQUAPONIC SYSTEM UTILIZING A FLOATING BEAD BIOCLARIFIER AND AIRLIFT TECHNOLOGY

Paul Begue* and Tim Pfeiffer
AST Filters Inc., New Orleans, LA
Correspond to: Paul.Begue@astfilters.com
 

Aquaponics is the combination of plant and fish culture in a recirculating water

environment. This system includes the production of fish and plants in an ecosystem that generates a stabilized environment where the fish waste is converted into a nutrient solution for plants growing in a hydroponic system.

At the AST greenhouse research facility (New Orleans, LA), a small-scale decoupled aquaponic systems was constructed and evaluated. For this demonstration unit, a single round 1 m3 polytank (~250 gal) was stocked with Tilapia (Oreochromis niloticus) at a density of 10 kg/m3 (0.08 lb/gal) and an initial size of 75 g (3-4 inches). The filtration system was composed of an Endurance 2000 bioclarifier which included 0.03 m3 (1 ft3) of EN floating bead media. The water flow through the filtration system was maintained at 45 Lpm (12 gpm) by airlift provided by a 46 watt linear air pump. The fish culture system was maintained between 25-28°C (77-82°F).The juvenile tilapia were fed a 2.0 mm floating pellet (50% CP) at a daily feed rate of 3% body weight.

The aquaponics system was de-coupled where a fish culture loop consisted of a single round 1 m3  polytank (~250 gal), a self-backwashing bio-clarifier, and a 0.12 m3 (34 gal) mineralizing tank. The plant culture loop consisted of a second 0.12 m3 (34 gal) sump tank, and 2 hydroponic raft culture raceways, each at 3 m2 (32 ft2). The recirculating water flow through each raceway tank was 30 Lpm (8 gpm). The plant culture tanks were maintained between 15-24°C (60-75° F). This plant system was stocked with 224 bibb lettuce plant seedlings at a density of 37.8 plants/m2. The economic feasibility of this de-coupled system depends on the specific costs of the raw materials including fish feed, electricity, water, lumber, filter, air pump, and tank costs. An economic analysis of fish and plant production in addition to water quality and feed conversion variables for the current status of the system will be presented.