What is Recirculatory Aquaculture System (RAS)? How it Works?

• The Smart Green Aquaculture Farm and Research Institute and the Recirculatory Aquaculture System (RAS) Facility were recently inaugurated in Hyderabad, Telangana.
• The facility is India’s first commercial-scale tropical RAS-based aquaculture farm for rainbow trout.
• It enables year-round tropical cultivation of rainbow trout and offers hands-on training in automation, biosecurity, and modern aquaculture systems.

About Recirculatory Aquaculture System (RAS)

• RAS is a land-based, closed-loop technology that filters and reuses water for fish farming in a controlled environment.
• Water Management: Advanced mechanical and biological filtration maintains optimal water quality while recycling about 90–99% of system water.
• Key Components: The system includes biofilters, mechanical filters, oxygenators, and UV/ozone units to control waste, toxins, and pathogens.
• Key Benefit: It enables high-density fish farming with minimal water use while reducing disease and biosecurity risks.
• Government Support: The Pradhan Mantri Matsya Sampada Yojana (PMMSY) provides financial assistance for establishing RAS units.

How It Works (The Cycle)

• Waste Creation: Fish in the tanks produce waste (ammonia) and consume oxygen.
• Mechanical Filtration: The water leaves the tank and passes through a filter (often a drum filter) to remove solid waste (feces and uneaten food).
• Biological Filtration: The water enters a biofilter containing beneficial bacteria. These bacteria convert toxic Ammonia (excreted by fish) into Nitrite and then into Nitrate (which is much less harmful).