The key difference between RAC and biofloc is that RAC mainly uses external filters to remove bacteria and larger solids from water in an aquaculture tank system, while biofloc mainly uses an extensive microbial community to remove unwanted chemicals and compounds from water in the aquaculture tank system.
Aquaculture is the farming of aquatic organisms. It plays an important role in increasing the global demand for seafood. Maintaining water quality is extremely important in aquaculture. Recirculating aquaculture system (RAC) and Biofloc are two systems used in aquaculture to ensure water usage, improve waste management, and enhance overall productivity. However, both these systems have different advantages and challenges.
CONTENTS
1. Overview and Key Difference
2. What is RAC
3. What is Biofloc
4. Similarities – RAC and Biofloc
5. RAC vs Biofloc in Tabular Form
6. FAQ – RAC and Biofloc
7. Summary – RAC vs. Biofloc
What is RAC?
A recirculating aquaculture system (RAC) is a system used to filter out unwanted particles and keep the tank’s water quality in order in aquaculture. RAC is equipped with external mechanical and biological filters that remove bacteria that produce nitrogen and larger solid particles from the tank system. It also uses ultraviolet lamps that sterilize the water in the tank system. Therefore, there will be no unwanted bacteria infecting the fish.
Figure 01: RAC
Furthermore, there are several benefits in the RAC, such as water conservation, improved waste management, water quality control, and year-round production. However, the challenges involved in this system are high energy consumption, the need for significant initial capital investment, and technical expertise.
What is Biofloc?
Biofloc is also a popular system as RAC that filters out unwanted particles and keeps the tank’s water quality in order in aquaculture. It uses an extensive microbial community to remove unwanted chemicals and compounds from aquaculture tank water. Moreover, it also uses an external filtration component. However, this external filtration component is used only to remove larger waste particles from the system.
Furthermore, the benefits of Biofloc systems include enhanced water quality, reduced feed cost, disease control ability, and increased production density. However, this system also has some challenges, such as higher oxygen demand due to high microbial activity, organic matter accumulation, and system complexity.
What are the Similarities Between RAC and Biofloc?
- RAS and Biofloc are two of the most popular systems in aquaculture when deciding how to ensure water quality.
- Both systems remove larger solid particles and other unwanted substances from the tank systems in aquaculture.
- They have external filtration systems.
- Both systems have benefits as well as challenges.
What is the Difference Between RAC and Biofloc?
RAC mainly uses external filters to remove bacteria and larger solids from the water in the aquaculture tank system, while Biofloc mainly uses an extensive microbial community to remove unwanted chemicals and compounds from water in the aquaculture tank system. Thus, this is the key difference between RAS and Biofloc. Furthermore, RAC is a very expensive system, while Biofloc is a comparatively cheap system.
The infographic below presents the differences between RAS and Biofloc in tabular form for side-by-side comparison.
FAQ: RAC and Biofloc
What is the RAS system in fish farming?
RAS is a technique of water purification in aquaculture. In RAS, water is recycled and reused after mechanical and biological filtration and removal of suspended matter and metabolites.
What is the principle of Biofloc?
The Biofloc principle is based on nutrient recycling by elevating the carbon-to-nitrogen (C/N) ratio, which stimulates the growth of microbial communities such as heterotrophic bacteria and algae within the system.
What are the different types of Biofloc systems?
There are two types of Biofloc systems based on exposure: those that get exposed to natural light and those that are not exposed to natural light.
Summary – RAC vs. Biofloc
Aquaculture involves cultivating freshwater, brackish water, and saltwater populations under controlled or semi-natural conditions. RAC and Biofloc are two systems used in aquaculture to ensure water usage and water quality. RAC mainly uses external filters to remove bacteria that produce nitrogen and larger solids from the water in the aquaculture tank system, while Biofloc mainly uses an extensive microbial community to remove unwanted chemicals and compounds from water in the aquaculture tank system. Thus, this summarizes the difference between RAC and Biofloc.
Reference:
1. Jamal, Mamdoh T, et al. “Biofloc Technology: Emerging Microbial Biotechnology for the Improvement of Aquaculture Productivity.” Polish Journal of Microbiology, U.S. National Library of Medicine.
2. “Recirculating Aquaculture System or Ras.” Aquaculture ID.
Image Courtesy:
1. “Recirculating Aquaculture System 2” By Narek75 – Own work (CC BY-SA 4.0) via Commons Wikimedia