How to Calculate Dissolved Oxygen Requirements For Shrimps in Biofloc System?

Biofloc technology is an innovative and sustainable aquaculture system that has gained significant attention over the years. Maintaining optimal dissolved oxygen (DO) concentration is critical for the growth and survival of shrimps in biofloc systems. In this article, we will discuss how to calculate dissolved oxygen requirements for shrimps in biofloc systems.

Step 1: Determine the Oxygen Demand of Shrimps

The first step in calculating dissolved oxygen requirements for shrimps in biofloc systems is to determine the oxygen demand of shrimps. The oxygen demand is the amount of oxygen required to maintain the respiration of shrimps in the biofloc system. The oxygen demand can be calculated using the following formula:

Oxygen demand = (biomass × respiratory rate × 24)/1000

where biomass is the weight of the shrimps in the biofloc system, respiratory rate is the amount of oxygen consumed by shrimps per unit weight, and 24 is the number of hours in a day. The result of this calculation is in grams of oxygen per day.

Step 2: Determine the Oxygen Transfer Rate

The next step is to determine the oxygen transfer rate of the biofloc system. The oxygen transfer rate is the rate at which oxygen is transferred from the air to the water in the biofloc system. The oxygen transfer rate can be calculated using the following formula:

Oxygen transfer rate = (KLa × surface area × ΔC)/1000

where KLa is the oxygen transfer coefficient, surface area is the surface area of the water in the biofloc system, and ΔC is the difference between the saturated DO concentration and the DO concentration in the biofloc system. The result of this calculation is in grams of oxygen per day.

Step 3: Determine the Required Aeration Rate

The final step is to determine the required aeration rate of the biofloc system. The required aeration rate is the amount of air that needs to be pumped into the biofloc system to maintain the desired DO concentration for shrimps. The required aeration rate can be calculated using the following formula:

Required aeration rate = (oxygen demand − oxygen transfer rate)/ (oxygen transfer efficiency × 24)

where oxygen demand is the oxygen demand calculated in step 1, oxygen transfer rate is the oxygen transfer rate calculated in step 2, and oxygen transfer efficiency is the efficiency of the aeration system. The result of this calculation is in liters of air per hour.

Step 4: Consider other Factors

In addition to the above steps, it is essential to consider other factors that affect dissolved oxygen requirements in biofloc systems, such as water temperature, salinity, and stocking density. As water temperature increases, the oxygen demand increases, and the oxygen transfer rate decreases. Salinity also affects the DO concentration because the solubility of oxygen decreases as salinity increases. High stocking density can also increase the oxygen demand in the biofloc system.

In conclusion, calculating dissolved oxygen requirements for shrimps in biofloc systems is a critical aspect of maintaining a healthy and sustainable aquaculture system. By following the four steps outlined above and considering other factors that affect dissolved oxygen concentration, you can calculate the required aeration rate to maintain the desired DO concentration for shrimps in your biofloc system.