RAS2020™ is a flexible, module-based recirculating aquaculture system with optimized production logistics, low operating costs and reduced footprint. The fish are farmed in a controlled environment based on state-of-the-art recirculation technology ensuring stability of the water parameters to optimize growth, reduce feed conversion ratio (FCR) and improve survival.

Advanced recirculating aquaculture system (RAS)


The RAS2020™ grow-out module is well suited for fish species such as salmon, trout, kingfish, sea bass and pike perch, among others. It makes it possible for fish production in almost any location and it requires relatively little intake water, thereby reducing the volume of discharge.

Based on well-tested Veolia technologies and processes such as Hydrotech™ drum filters, AnoxKaldnes™ moving bed biofilm reactor (MBBR), degasser and control system, RAS2020 has brought in optimal flexibility in recirculation aquaculture systems (RAS) resulting in minimum handling and moving of the fish using fish pumps, reducing stress.

The adjustable water velocity in the two round circular tanks secures optimal conditions for the fish in the entire water column. It is generated by flowmakers which secure an exchange of water in each tank section in less than a minute. The velocity of water is adjusted to size and species, which gives optimal fish welfare and subsequently high quality fillets.

With a total footprint of only 3,340 m², RAS2020 is extremely compact, allowing the same volume of fish to be produced with  only half the footprint compared to other conventional RAS designs on the market.

How RAS2020 works

The circular flow of water in the tank, together with the movable grids, is a unique design that results in great flexibility with regard to species and production logistics. The tanks are separated by grids through which water can flow, allowing an optimal water speed to be maintained with respect to fish size in the two tank loops.
The movable grids allow for flexible tank sizes so that as the fish are harvested from the final section, the space can be redistributed to the other fish, thus making use of the full tank space. 

The water is continuously circulated, treated, and reused, which reduces the water demands and allows for the water to be maintained at the correct temperature and quality for optimal fish rearing.
The water flow is treated first by drum filter to remove large particles. Then there is a moving bed bioreactor, which uses bacteria and other microorganisms to break down organic matter and remove nitrogenous compounds, such as ammonia and nitrite, from the water.
There is ozonated protein skimming to remove excess bacteria from the water and provide water polishing.
The carbon dioxide is off gassed and oxygen is added back using an energy efficient design. 

The water is returned to the fish via inlets throughout the tank. The water speed and distribution is controlled using propellers to create evenly distributed conditions. 

Features and benefits

  • Annual production capacity 1,200 metric tons (1,322 US tons).
  • Maximum daily feeding 4,200 kg (9,300 lb).
  • Maximum standing stock 450 metric tons (496 US tons).
  • Maximum water consumption 65 m3/hour (260 gpm).
  • Water quality and discharge tailored to the client.
  • Up to 99.5% of the water is treated and recirculated.
  • Up to 50% reduced footprint with compact design.
  • Highly-controlled and uniform flow velocity to mimic a natural aquatic environment.
  • Efficient facility design that ensures biosecurity.
  • Reduced operating and utility costs.
  • Reduced handling to minimize fish stress.
  • Optimized feed conversion ratio.


High quality water systems for production, process and manufacturing uses.
Solutions allowing the use of treated wastewater for beneficial purposes.
Municipal drinking water systems and management of surface and ground water.
Technologies, services and process expertise to meet environmental requirements, remove contaminants and transform wastewater into a resource.


Bundling high performance specialty chemicals, innovative dosing and controlling equipment with related expert support.

Resources & Product range

The RAS2020 grow out solution can be supplied by one or two modules with the following options:

  • Hatchery - Post smolt facility
  • Intake water treatment plant
  • Wastewater treatment plant


Salmon farming using recirculating systems offers many profitable investment opportunities, with attractive growth potential. This economy has attracted investments from large distribution companies as well as from private investors who wish to be involved on a sustainable project. Our RAS systems offer the potential for increased efficiency, reduced environmental impact and improved control over water quality, resulting in optimum conditions for healthy fish, which in turn results in delicious food. As the demand for fish increases, customers come to us to invest in sustainable solutions for this growing industry. Our strength is our experience in innovative land-based design and our standardized, modular solution from egg to harvest RAS.

Thomas Hofmann witth a salmon fish

Thomas Hofmann

Business and sales development manager

FAQ about RAS2020™

How can land-based aquaculture help meet the increased demand for fish?

“The demand for quality seafood and sophisticated consumer purchasing trends have increased. This, combined with the environmental and financial risks of off-shore aquaculture, creates the need for farmers to gain greater control over their operations. Land-based RAS (Recirculating Aquaculture Systems) is a solution for aquaculture companies to reduce risk, while maximizing profitability.”

Why is aquaculture important?

“Overfishing is one of the greatest threats facing the oceans today. The damage it causes goes far beyond the marine ecosystem, as billions of people depend on fish as a source of protein for food. The current world population of 7.3 billion is expected to reach 8.5 billion by 2030, and as it soars so will the demand for food, putting our oceans at even greater jeopardy. At Veolia Water Technologies, as part of our "Resourcing the world" mission, we believe that sustainable aquaculture could be the key to feeding our growing population while easing pressure on wild fish stocks and thus protecting the oceans.”

How are recirculating aquaculture systems (RAS) more sustainable than traditional aquaculture?

Recirculating aquaculture systems (RAS) are more sustainable than traditional aquaculture methods for several reasons.

  • Water conservation: RAS systems can be designed to minimize water usage and minimize the amount of waste produced, which can lead to cost savings and increased efficiency compared to traditional open-water systems.
  • Reduced environmental impact: RAS systems allow for the production of aquatic animals in a more controlled and contained environment, which can reduce the impact on the surrounding environment. This can include reduced discharge of waste, chemicals, and disease into the environment.
  • Improved control over water quality: in RAS systems, water quality can be closely monitored and controlled, which can help to maintain the health and well-being of aquatic animals and reduce the risk of disease outbreaks.
  • Increased production: with the optimal conditions of RAS systems, fish grow faster and more efficiently than in the wild or in fish farms that are open to the elements, such as net pens. With sufficient water treatment, fish can also be kept in higher densities than in other forms of farming, creating more output on a small footprint.
  • Enhanced biosecurity: in the closed environment of the RAS, the fish are not exposed to parasites or disease as they are in nature. This reduces the need for medication, particularly for antibiotics, which can be avoided in a well run RAS plant. 

Case Studies

Swiss Alpine Fish - Sustainable salmon production using RAS2020™ recirculation.

Based in Lostallo, Switzerland, Swiss Alpine Fish AG raises fish to high quality and environmentally friendly standards. The company chose to invest in our modular recirculating aquaculture system, RAS2020, which ensures that up to 99.5% of the water is treated and recirculated in a land-based system. In this way, hardly any discharge reaches the local water environment.

Sashimi Royal

The Danish aquaculture company Sashimi Royal, has started production in their new land-based kingfish facility located on the Northern coastline in Denmark. The facility features Krüger’s unique grow-out solution, RAS2020TM, which allows for the sustainable production of this valuable species with regards to high environmental standards.


The Norwegian aquaculture company Fredrikstad Seafoods AS, owned by Nordic Aquafarms AS, relied on Veolia Water Technologies' expertise for their first land-based Atlantic salmon grow-out facility project in Norway. The facility was designed with several modules of our patented modular recirculating aquaculture system RAS2020™ ensuring highly efficient production and superior environmental standards in order to achieve sustainable production.