What is the Optimal DO Value for Vaname Shrimp? Check Here!

Like all living things, vannamei shrimp need oxygen to breathe in water. The optimal DO value for vannamei shrimp describes the amount of dissolved oxygen in the water that can be used by vannamei shrimp to breathe. 

This is the reason why managing the optimal DO value for vannamei shrimp is one of the factors that play a role in maintaining the quality of the aquaculture water and the cultivation itself. Shrimp that live in water with optimal DO can certainly grow well. Conversely, if the DO value of water is low or too high, the shrimp cannot develop optimally. 

Check out the full explanation here!

What is DO (Dissolved Oxygen)?

Dissolved oxygen or Dissolved Oxygen (DO) is the concentration of dissolved oxygen in water. This dissolved oxygen comes from the photosynthetic activity of phytoplankton and diffusion from the air.

Dissolved oxygen plays a role in the process of respiration and the biological processes of organisms in pond water such as shrimp, plankton and bacteria. The following factors affect oxygen levels in the water:

1. Respiration. Dissolved oxygen will be consumed by the shrimp for the respiration process or the exchange of oxygen and carbon dioxide in the shrimp's body. The bigger the size of the shrimp, the greater the oxygen requirement. Oxygen will also be consumed by plankton for the respiration process. During the day, plankton produces oxygen through the process of photosynthesis, while at night plankton uses it for respiration.  
2. Biological processes by bacteria. Oxygen will be utilized in biological processes that occur in waters such as the nitrogen cycle, carbon cycle and phosphate cycle.
3. Oxygen diffusion. Oxygen will experience diffusion from water to air when oxygen levels in the water experience excess and or deficiency. The oxygen diffusion process will occur when the amount of oxygen produced by plankton is small but consumed by bacteria is too much, and when windy weather causes waves or ripples on the surface of the water. This diffusion process is assisted by the movement of the pinwheel. 

In the cultivation process, the use of aeration such as pinwheels and blowers It is very important to increase dissolved oxygen levels and aid in the diffusion of oxygen from air to water. If the availability of oxygen in the waters is reduced or a little, the metabolic processes in pond waters will be disrupted.  

Optimal Value of DO in Vaname Shrimp Ponds

The optimal DO value for vannamei shrimp is > 4-5 mg/l. Dissolved oxygen content that is low or <1.5 mg/l will be lethal or lethal to shrimp.

To determine DO levels in pond water, farmers can use a DO meter tool (Dissolved Oxygen Meter) or test kits DO. Using the DO meter is quite easy. Farmers only need to dip the DO meter pen into the water, then wait until the numbers shown on the DO meter monitor stop. Farmers can check at night because at night the shrimp and plankton use oxygen for respiration. 

One of test kits The DO that you can use to test DO levels in pond water is Paralab Test Kit DO. How to use test kits The DOs are as follows: 

1. Take a water sample using a winkler bottle until it is full, then close it. Make sure there are no air bubbles in the bottle.
2. Open the winkler bottle cap and add 10 drops of reagent 1 and 10 drops of reagent 2.
3. Close gently so that there are no air bubbles in the winkler bottle.
4. Let the lumps settle for 5 minutes.
5. Add reagent 3 as much as 20 drops.
6. Close gently so that there are no air bubbles in the winkler bottle, then shake until the precipitate dissolves completely.
7. Take 20 ml of solution using a measuring cup and put it in the Erlenmeyer.
8. Titrate using reagent 5 until the color changes to yellow.
9. Add 3 drops of reagent 4 so that the color changes to blue-black.
10. Titrate again with reagent 5 until the blue-black color disappears. Count the number of drops of reagent 5 used.

After this whole process is complete, you can calculate DO in water using the number of drops of reagent 5 used. How to calculate the DO value of a water sample is to use the following formula:

 DO Value = Number of Drops of Reagent 5 X 0.407

For example, you use 18 drops of reagent 5. That means, the DO value of your pond water is 18 x 0.407 = 7.326, rounded up to 7 ppm.

Causes of Decreasing Dissolved Oxygen (DO) in Ponds

Low oxygen or DO levels will harm shrimp because oxygen is useful for sustaining shrimp life. Low oxygen levels will also cause toxic gas in pond sediments. Bacteria need oxygen to carry out biological processes. However, when the water wheel does not supply oxygen to the bottom of the pond, the bacteria cannot carry out biological processes. As a result, the process of decomposition of organic matter by bacteria will cause the sediment to become anaerobic. 

Then, what causes the oxygen in the pond to decrease?

1. blooming plankton. At night, plankton does not carry out photosynthesis and requires oxygen for respiration. If the plankton is too abundant, there will be competition for oxygen between the shrimp and plankton in the pond, so that DO decreases more quickly. 
2. Improvement of organic matter. When there is an increase in organic matter, the decomposition or decomposition of organic matter is greater and oxygen consumption will increase, so that oxygen in the waters decreases rapidly. 
3. Shrimp density is high. The higher the shrimp density, the more oxygen will be used in the pond, so the oxygen concentration will decrease.
4. High temperature. The higher the pond water temperature, the higher the oxygen demand for the shrimp because the shrimp metabolism increases.

How to Overcome Decreased Dissolved Oxygen (DO) Levels

Here's how to deal with decreased oxygen levels:

1. Use pond support facilities for aeration, such as waterwheels and blowers. These supporting facilities will help maintain dissolved oxygen levels in pond water, as well as support the aerobic decomposition of organic matter and nitrification by bacteria. The aeration system also produces water currents which help the process of agitating the mass of water, so that oxygen levels in pond water can increase.
2. Keep the amount of phytoplankton in the pond. Phytoplankton will produce oxygen in the water through the process of photosynthesis, so that it can participate in increasing DO in pond water.
3. Control the water quality levels in the pond, such as temperature, pH, and brightness, so that they remain optimal.
4. Increase the aeration system at night. At night, oxygen will decrease due to the absence of photosynthesis. Therefore, there needs to be countermeasures so that oxygen levels in pond water do not fall.

Dissolved oxygen or Dissolved Oxygen (DO) needs to be controlled so that its levels in pond water remain optimal and in accordance with the needs of the shrimp. If not maintained, low oxygen levels will cause water quality to deteriorate and lead to the death of shrimp. 

You must check the dissolved oxygen in the pond, especially at night. At night, oxygen will decrease because there is no photosynthesis and only rely on the aeration system. 

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