Recirculating Aquaculture Systems (RAS)

Skretting leads the way in the development and supply of feeds designed specifically for recirculating aquaculture systems (RAS). This journey dates to before 2009, when we became the first company to launch commercial RAS feeds. We have continued to pioneer advancements in this space ever since.  

About RAS

Recirculating Aquaculture Systems are land-based aquaculture facilities that reuse water by cycling it through a filtration system so it can be used again. The highly sustainable nature of these operations reduces the amount of water and space needed for aquaculture. The population of RAS-based facilities has grown exponentially and more are being implemented worldwide, year after year. The increased use of RAS represents a paradigm shift for aquaculture as they are becoming the standard, not only for early stages in freshwater, but the entire life cycle for many species.

RAS farming can be a fully controlled system offering a number of advantages and opportunities. Firstly, it alleviates the need for aquaculture to be in an existing environmental ecosystem that complements the species. This allows the convenience of diversity with species and location. Secondly, the overall health and growth of the species can be improved as water quality is carefully monitored to ensure conditions remain optimal. Some of the parameters monitored regularly include oxygen, carbon dioxide, pH, temperature, nitrite, nitrate and ammonia. Finally, RAS also requires very little water and space making it much more sustainable in comparison to traditional methods.

RAS come with their own unique challenges, in particular maintaining consistent water quality. The filtration of organic matter (physical and dissolved waste) produced by the aquaculture species needs to be efficiently removed by the system in order to reduce the water pollution. The system uses an array of filters including a live microbial filter (bio-filter) that is key in removing and reducing harmful dissolved waste. It is essential that all other filters remove excess waste and nutrients so that the microbial balance remains in this filter. It is imperative to only use optimal diets to decrease waste output and maximise filtration in order to maintain high quality water conditions thus improving growth, FCR, product availability and increased biomass.

Our research facilities for RAS

RAS equipment

RAS research

We have invested many research resources into RAS because of their potential to enhance the sustainability of the aquaculture industry. We have three dedicated RAS-based research facilities across the world, each of which has a unique focus. Our central RAS team at Skretting Aquaculture Innovation (AI) is comprised of many knowledgeable researchers, specialising in these systems.

Learn more about Skretting RAS research


One of our most recent innovations for the RAS segment is our RCX concept. RCX builds upon our previous market-leading range, RC, but goes further by ensuring consistent structural integrity through a certified quality assessment.

See our RAS products