rAS

Although, RAS systems in comparison with the classical systems, are much more advantageous by requiring less water needs, intensively stocking capacity, short time of production period in order to provide the optimum conditions of water levels and parameters for the fish, it brings more equipment and energy innovations. Just because of these equipments and energy, the innovation and management costs are always higher than classical systems.

RAS systems are considered to be counted on 4 main systems;

  • Hatchery Unit: A fish hatchery is a place for breeding, hatching, and rearing through the early life stages of fish.
  • Nursery Unit: The fish raised in nursery unit are called juveniles, where juveniles occur inrelatively high densities has been considered as nursery.
  • Grow-Out Unit: The unit where the fish is stocked and fed intensively by providing the optimum water conditions for sales.
  • Off-Odour Unit: The unit where the fish is processed with ozone gas in order to be cleaned of their feed and ammonia odour on their flesh when they the fish is ready to be sold. Better to keep the fish in this unit 3-4 weeks.

In order to grow the fish in short time of periods water conditions should always be kept in optimum conditions. Therefore, for this reason, the water in RAS systems is cleaned by flowing through many filtration systems and the temperature is kept constant by heating and cooling.

Here are the filters that are existing in the systems.

  • Mechanical Filters: Drum filters, sand filters, bag filters, automatic filters etc. They are used for holding the solid and the suspended particules in the system.
  • Biological Filters: They are used for the harmful ammonia and ammonium components to be converted by the bacteria in order to be released from the system.
  • UV Filters; They are used for neuralizing and makin ineffective of all kinds of living microrganisms like bacteria, virus present in the system.

Besides, in RAS systems the procustion is applying intensively, hence the oxygen requirement is high. That’s why there must always be an oxygene reinforcements externally to keep the oxygene level in high levels. Fort hat, oxygene tubes, oxygene generators and liquid oxygene silos are used.