Tasmanian Eel Exporters – Eel Grow Out RAS

The Finlayson family engaged FBD to build a recirculating aquaculture system to grow-on eels captured in the wild.

The RAS includes 20 x 9000L Polymaster Tanks with a filtration system designed around a peak feeding rate of 525 kg/day. Water is pumped into the tanks through 4 x 960watt Pentair U.V. Sterilizers, then through an oxygen cone (FBD Model 1) on each tank to maintain stocking densities up to 150kg/m3. Water leaving the tanks is gravity-fed via floor channeling, to a Faivre 16/120 Drum Filter fitted with 36µm screens, and then through a Moving Bed Bioreactor (MBBR) and bio block degassing unit into the sump. Additional filtration is provided by an RK600PE Freshwater Fractionator, to which ozone (RK2, 15g/hr) is added to enhance water quality control.

Further control over dissolved solids (TDS) is ensured by the inclusion of an AST (Aquaculture System Technologies) Propeller-wash Bead Filter, with an automatic backwash control system. Australian designed and manufactured Turbine pumps were chosen for their energy efficiency, serviceability and reliability. They also negate any concerns over nitrogen super-saturation given their submersed design. Feed is delivered automatically via an Arvo-Tec feeding system over 24 hours at 1-3% of biomass per day.