Fish farm equipment provider right now: Controlling parasites in flowing aquaculture is one of the most long-standing problems of producers of the global community, especially in the systems whose water flow is continuous, i.e., flow-through, semi-recirculating and hybrid RAS aquaculture systems design (Power et al., 2025). This unceasing flow of water is not only vital in oxygenation but also in the removal of waste, which also provides effective routes through which parasites spread to various tanks and production lines. Many parasites possess mobile infective stages adapted specifically to aquatic hydrodynamics, allowing them to exploit water currents as transport mechanisms to reach new hosts (Mouritsen, 2025). As aquaculture becomes increasingly industrialized, the consequences of even moderate parasitic infestations have grown more severe because stocking densities are higher, production schedules are tighter, and biological stress tolerance among cultured species can be easily exceeded (Madsen & Stauffer, 2024). These pressures have made engineering-based parasite control a necessity rather than an optional management strategy. Among the technology-driven solutions available, the combined use of flow-rate optimization and ultraviolet sterilization has emerged as one of the most effective ways to interrupt transmission cycles and stabilize health performance in flowing aquaculture environments (Li et al., 2023).
Environmental compliance and sustainability are prominent advantages of RAS systems. In traditional pond farming, residual feed and feces are directly discharged, causing eutrophication of surrounding water bodies and ecological pollution. Moreover, the scale of farming is strictly restricted by environmental policies. RAS systems treat farming waste through solid-liquid separation and microbial degradation, achieving zero discharge or resource utilization of pollutants, fully meeting modern environmental protection requirements. In addition, the closed farming model avoids the risk of invasive species and cross-infection of diseases, making product quality easier to control and meeting the demands of food safety.
Ozone alone cannot maintain a stable RAS environment. Fish release ammonia continuously through their gills and metabolic waste, and even low concentration of ammonia impairs gill function, suppress appetite and inhibit growth. Due to this fact, biological filtration is the second key pillar of the dual-treatment approach. In the biofilter, Nitrosomonas, Nitrobacter and Nitrospira are specific nitrifying bacteria that will turn ammonia to nitrite and subsequently to nitrate via the nitrification process (Oshiki et al., 2022). This bio-chemical conversion is necessary in preserving a safe environment in high-density aquaculture plants. Due to ozone being sensitive to these bacteria, physical separation between ozone contact and biological filtration must be maintained during system design. In contemporary RAS, ozone is sprayed into a separate chamber where it combines with water then flows through a degassing unit that removes all the remaining ozone. This step is only done after which treated water can be admitted into the biological filtration process(Xiao et al., 2019).
Flow-through aquaculture systems will undoubtedly play a more vital role in the future development of the aquaculture industry. They will not only meet the growing demand for high-quality aquatic products but also drive aquaculture towards modernization, intelligence, and green development, achieving a win-win situation in terms of economic, social, and ecological benefits. It is believed that with the joint efforts of all parties, the future of flow-through aquaculture systems will be full of unlimited possibilities, making a greater contribution to the sustainable development of global fisheries. RAS (Recirculating Aquaculture System), as a core technology in modern aquaculture, has multiple advantages over traditional pond farming due to its efficient resource utilization and precise environmental control. It has become a key direction for the transformation and upgrading of the aquaculture industry. Its core advantages are mainly reflected in four dimensions: resource utilization, farming efficiency, environmental protection and safety, and risk resistance. See a lot more details at fish farming supplies manufacturer.
Shandong Wolize Biotechnology, with 15 years of experience, ISO/CE certifications and university partnerships, designs and delivers turnkey RAS, high-density flow-through and aquaponic systems. Our equipment operates in 47 countries, powering 22 large-scale projects over 3,000 m³ each. We offer design, installation, training and lifelong support, helping farmers triple yield, cut costs 30 % and meet ASC/BAP standards. The Recirculating Aquaculture System (RAS) is a modern aquaculture technology designed to provide a stable and suitable growth environment for aquatic organisms through efficient water treatment and resource recycling. This system is widely applied in various types of aquaculture, including fish, shrimp, and crab farming, and boasts significant environmental, economic, and production advantages.
To ensure the success of the dual ozone-biofilter system, it is important to maintain the right operation parameters. The values of oxidation-reduction potential in the ozone contact chamber are normally 275 to 320 millivolts (mV). This spectrum aids in efficient reduction of organic matter without generating any undesirable reaction byproducts (Davidson et al., 2021). Before the ozone unit, mechanical drum filters of sixty to one hundred microns in size are used to remove large, suspended solids to enhance ozone efficiency by decreasing the organic load. Optimal values of dissolved organic carbon are four milligrams per liter because beyond this level, the water fails to be clear and promotes the growth of microbes. The concentration of dissolved oxygen below the ozone chamber is usually more than nine milligrams per liter since ozone decomposes naturally to produce oxygen. Having high dissolved oxygen levels greatly improves fish metabolism as well as the rate of nitrification. Most importantly, the amount of residual ozone entering the biofilter should also be zero, this is achieved through constant monitoring to ensure that the nitrifying bacteria is not damaged.