CHALLENGE:

During summer, surface water can become significantly warmer than deeper water, increasing stress on fish and affecting water quality. Field measurements showed surface temperatures near 24°C, while water at approximately 18–20 m depth was around 9–10°C.  The farm needed a system that could:

The hatchery needed a solution that could:

• Bring colder deep water into the net pen
• Improve Water Circulation
• Support Dissolved Oxygen
• Reduce energy use
• Minimize submerged mechanical equipment

THE SOLUTION

FloNergia installed a prototype upwelling system using FloMov™ airlift pumps, with 1m risers, allowing colder water to be drawn from 16 m depth and delivered into the fish-production zone without any submerged mechanical components.

The system was tested in a commercial net pen together with temperature, dissolved oxygen, pH and environmental monitoring.  

RESULTS

• 1.5°C reduction in water temperature within 3.5 hours
• Dissolved oxygen increased from 8.08 to 9.23 mg/L
• Full scale system projected to achieve a 5°C temperature reduction across four 50 ft × 90 ft net pens
• Projected ~94% energy savings compared with conventional upwelling systems
• Projections based on validated field data and computational modelling

WHY IT WORKED

Traditional upwelling systems often rely on mechanical pumps to move deep water, requiring significant energy and submerged equipment. FloMov™ uses low pressure air to lift large volumes of water through a submerged riser, bringing cooler water from depth while simultaneously supporting circulation and aeration.

As air rises through the riser, it creates a gas liquid mixture that lifts surrounding water upward. This process moves deep water into the fish production zone while increasing air water contact and supporting oxygen transfer. With no submerged moving parts, the system provides reliable water movement with minimal mechanical equipment.

By optimizing the riser configuration, air flow, and operating depth, FloNergia was able to achieve effective upwelling while significantly reducing the energy required compared with conventional systems.

Advancing Climate Resilience in Aquaculture

This installation demonstrates how FloMov™ airlift technology can support climate resilient aquaculture by bringing cooler deep water into fish production areas while improving circulation and dissolved oxygen. With projected energy savings of approximately 94%, the system offers a more efficient approach to managing water temperature and quality during warm summer conditions.

Planning a Similar Aquaculture Project?

Talk to a FloNergia applications engineer about improving water temperature, circulation, aeration, and energy efficiency at your facility.