Aeration is of immense importance in aquaculture. For the purpose of biofloc aquaculture, BFT or biofloc technology is the most appropriate solution for aeration. Biofloc technology is a specialised technique of enhancing the quality of water in aquaculture by creating an appropriate balance between carbon and nitrogen in the aquaculture system. BFT or biofloc technology has gained a lot of importance in recent times as it is a sustainable method to control water quality along with the added advantage of producing proteinaceous feed in situ. BFT is an environmentally friendly aquaculture technique that is based on in-situ microorganism production. Fishes and shrimps are grown in an intensive way with zero or minimum water exchange, where farming is done in minimum of 300 g of biomass per square meter.
How Does the Biofloc System Work?
Biofloc system makes use of a counter-intuitive approach. The system allows solids as well as associated microbial community to accumulate in water. As long as there is enough mixing and aeration for the maintenance of an active floc in suspension, the quality of water can be controlled.
Factors Affecting Aeration in Aquaculture
Some of the essential factors that affect aeration in aquaculture are as mentioned below:
- The species chosen for BFT or biofloc technology
- The concentration of micro organisms in the entire system. These micro organisms are categorised into:
- Aerobic micro organisms that utilise dissolved oxygen in water
- Anaerobic micro organisms that utilise nitrogen compounds
- Photosynthetic micro organisms such as algae that produce dissolved oxygen in the presence of sunlight
- The temperature of water
- The surface area of water versus the volume of water
- Depth of water
- The salinity of water
- The total amount of organic as well as inorganic waste in the entire aquaculture system
- Type of external aeration provided
Important Points to Consider in Artificial Aeration
Here are a few of the most important points to consider in artificial aeration:
- At the beginning, the biomass or stocking density needs to be considered
- The movement of water is a matter of immense importance. Low water movement might cause reduced aeration of nitrifying bacteria. On the other hand, very high movement of water can cause unnecessary movement and fatigue of the animal, thereby increasing their oxygen requirement
- The depth of water needs to be considered along with the size of bubbles produced in aeration
- The users also need to consider the path of the bubbles and the time in water, particularly in case of diffused aeration
- Ultimately, the duration for which aeration is provided needs to be considered in biofloc aquaculture