Aquaculture is the most rapidly growing sector of food production worldwide
According to the FAO (Food and Agriculture Organization of the United Nations), current global food production needs to increase 70% by 2050 in order to feed 2 billion additional people.
The growth of aquaculture will become an increasingly important part of that future food supply, while paying particular attention to environmental concerns.Higher Fish and Prawns density can lead to pathogen increase which is a significant threat to aquaculture operations.
According to a 2012 'World Review of Fisheries and Aquaculture report', disease outbreaks in recent years have affected marine shrimp farming in several countries in Asia, South America and Africa, resulting in partial or sometimes total loss of production.
Ozone is a very powerful bactericide and viricide and, unlike other agents, it leaves no undesirable residues. An ideal method of disinfecting water is by Ozonation in a contact tank prior to use.
In general, the main reasons for using ozone in water treatment are:
- Partial or total oxidation of dissolved matter.
- Precipitation of dissolved matter.
- Micro-flocculation of organic matter.
- Destabilisation of colloidal matter.
Unlike disinfectant agents such as chlorine or any of its derivatives, oxidation with ozone leaves no hard to handle or toxic residues requiring subsequent complex treatment. In practice, Ozone immediately starts to attack the oxidizable components when it comes into contact with. This property makes it a very powerful disinfectant because the process only leaves behind "oxygenated" products and oxygen. It is particularly well suited for applications such as hatchery water where the presence of undesirable elements after treatment could have grave consequences. Lotus Ozonators have been successfully deployed and are currently being used in several private high-tech hatcheries down the coast line from Kakinada to Chennai to Marakkanam.
Using Ozone has been proven to
- Significantly increase yield per cycle.
- Drastically reduces the aeration time required when compared to Chlorine disinfected water.
- Increases the number of cycles or batches per year.
- Results in Increased overall hatchery productivity.
Ozone is increasingly used in aquaculture due to its numerous advantages over traditional water treatment methods. The use of ozone is the most effective method for providing high-quality water for Fish and Prawn farming.
Disinfection by Ozone can reduce the risk of disease in aquaculture systems and results in less need for vaccination, less use of antibiotics and leads to higher growth rates and decreased mortality.
As the strongest, technically producible oxidising agent it fulfils further functions apart from disinfection. During the Ozonation process Ozone is consumed completely and breaks down again into oxygen.
- Increase D.O. (Dissolved Oxygen).
- Reduction of Diseases, reduce stress on the Fish and Prawn.
- Reduce Ammonia and Nitrite.
- Faster Growth Rate and Lower FCR.
- Better quality of Fish and Prawns.
- Higher Standard of Environmental Control and much better pond bottom.
Factors influencing the Dissolved Oxygen content of pond water
Dissolved Oxygen content of the water in Fish and Prawn ponds is one of the most important parameters of water quality, as the oxygen is a vital condition for all the organisms living in the water. The DO content in the Fish and Prawn ponds varies over a period of 24 hours. The photosynthesis starts gradually from the early morning hours while the DO content of the water is increasing. The maximum value can be observed early in the afternoon.
From the late afternoon hours photosynthesis is rapidly decreasing and is stopped after dark. The DO content of the water is also decreasing during this period. Also at night time the algae go through the respiration cycle (opposite effect of photosynthesis), giving out CO2 and consuming the DO.
This means that during night times the DO levels keep falling and are lowest in the early morning hours. This puts severe stress on the Fish and Prawns. Especially during moulting periods. It is extremely important to maintain sufficient DO levels at all times.
This is accomplished by keeping the Lotus Ozonator running through the night. Maybe turned off during afternoon hours, between 10 AM and 3 PM. This helps to keep the DO levels at a steady level and not allow it to go up and down causing stress.
Fish and Prawns are naturally stressed during moulting, but if the DO levels are lower than 4 ppm (mg/l), it increases the stress. The opposite is also true, where by having sufficient DO levels, the Fish and Prawn are less stressed, feed better, and grow faster.
Ozone is used in fresh and salt-water (marine) aquaculture to improve the water quality by reduced organic load, bacteria, viruses, fungi, etc.,
Ozone is a very powerful oxidizer with several times the oxidizing potential than that of chlorine bleach and several thousand times faster in action. Hence, very short contact time is required.
As a natural disinfectant, Ozone is replacing traditional chemical oxidants in a growing number of industrial processes including food and beverage industry, dairy and seafood processing. Ozone destroys all common pathogenic organisms through natural processes of oxidation, disinfection, and decomposition to Oxygen (O2).
Because Ozone is powerful in cold water, it reduces the need for hot water and steam in turn saving water, energy, time and money.