A recirculating aquaculture system is configured for growing aquatic animals. The system includes an inlet conduit, a tank, a water treatment unit, a clarifier, and an outlet conduit. The tank is in fluid communication with the inlet conduit to receive water displaced from the inlet conduit. The tank also contains water and aquatic animals. The water treatment unit is arranged within the tank and includes algae capable of removing aquatic animal waste from the water within the tank. The clarifier is in fluid communication with the tank to receive displaced water from the tank. The clarifier is also configured to remove solid waste from the displaced water. The outlet conduit is in fluid communication between the clarifier and the inlet conduit.