The Critical Role of Water Quality in RAS Systems: Insights from a 36-Year Veteran
1. Understanding the Importance of Water Quality
As a trained veterinarian with 36 years of experience at Skretting, I’ve engaged with numerous customers, and one persistent concern is water quality. It serves as the lifeblood for aquatic species, providing oxygen, removing carbon dioxide, and facilitating the removal of metabolic waste products like ammonia. Water also hydrates fish and contributes essential minerals while supporting their physical structure.
Farmers often express that their fish’s health and well-being are heavily influenced by the system’s load, which includes waste from digestion. Soft feces can quickly disperse, overwhelming mechanical filters and eventually burdening bio-filters, reducing their effectiveness. This not only impacts UV treatment systems but also leads to inefficient production overall. A major breakthrough in RAS diets is the formulation aimed at enhancing fecal stability and preventing dispersal, thereby improving waste removal and maintaining water quality. Ultimately, lower organic loads translate to reduced bacterial growth, minimizing gill diseases and improving metabolic efficiency for optimal fish growth and reduced costs.
2. The Evolution of RAS Feeds in North America
Skretting North America took a pioneering leap in 2011 by being among the first to utilize RAS feeds in grow-out systems, followed by introducing RCX feeds in 2017 with Optiline RCX Organic for Superior Fresh. Our commitment to good water quality, fish welfare, and growth efficiency is palpable, particularly in RAS-based farming, which requires meticulous system management. Helping farmers improve their profitability while simultaneously lessening their workload is a gratifying aspect of our work.
3. The Symbiotic Nature of RAS Systems
RAS transcends the notion of merely a land-based fish farming facility; it’s a delicate balance between the fish, their biologic ecosystem, and the sophisticated engineering systems in place. Feed quality impacts all three facets. Unlike traditional systems, RAS brings unique challenges: fecal matter can overload bio-filters, raising oxygen demands, inducing off-flavor compounds, and increasing energy expenses. By focusing on highly digestible feeds and employing specialized faecal binders, we can enhance waste removal before it affects biological systems, leading to decreased energy use and oxygen demands.
4. Continuous R&D for Product Improvement
Skretting has been at the forefront of RAS feed innovation, having developed specialized RCX feeds tailored for intensive systems. Our dedicated research farms in Lerang, Norway, and Pargua, Chile, enable us to assess novel ingredients and their effects under actual conditions. This ongoing research ensures we remain leaders in advancing RAS feed technologies.
5. A Memorable Encounter in RAS Engineering
One standout interaction occurred in 2004 when I met Dr. Steve Summerfelt, a renowned RAS systems engineer at the Freshwater Institute. His mentorship provided invaluable insights into the functional attributes and limitations of RAS systems at a time when they were becoming increasingly pivotal in North American salmon smolt production. This knowledge directly contributed to the launch of Skretting’s Nutra RC line of fry feeds in 2011, which vastly improved water quality in RAS systems.
Fast forward to 2018, Dr. Summerfelt joined Superior Fresh as Chief Science Officer and reached out regarding our new RCX concept. While eager for his feedback, there was an unavoidable pressure knowing he was a pioneer in this field. Thankfully, his response was overwhelmingly positive, confirming our feed’s effectiveness in enhancing growth and maintaining water quality. This success underscores the need for continuous evolution in feed design as RAS systems progress.
Image: Steven Backman credit Skretting
