Sunday, June 12, 2016

Preparation of aeration system in shrimp ponds and time use

Preparation of aeration system in shrimp ponds and time use











a. Placing the paddle wheels

- 1.5 m from the bank.

- The distance between two paddle wheels is 60-80 cm; staggering the paddles.

- Depending on the shape of the pond, arrange paddles appropriately to create a better flow and provide enough oxygen for the demand of shrimp.

b. The number of paddle wheels

- For black tiger prawn farming, guided in Table 2

Table 2: The number of paddle wheels in pond for black tiger prawn farming

Pond area (m2)
Density: 
15-20 prawns
Density: 
20 - 25 prawns
The rate of rotation
(cycles/min)
3.000
20 – 25 paddles
25 - 30 paddles
100 - 120
5.000
50 – 60 paddles
60 – 80 paddles
100 - 120


- For whiteleg shrimp farming, guided in Table 3:

Whiteleg shrimp has a large demand for oxygen. Therefore, it is depending on the stocking density to design aeration systems with paddle wheels, or a combination of plastic paddles wheels aerators with spiral aerators or other types of paddles to provide enough oxygen for shrimps in ponds. The rotation of the plastic paddles should be more than 120 cycles/min (see Table 3).

Table 3: The number of paddle wheels in pond for whiteleg shrimp farming

Pond area (m2)
Density (shrimp/m2)
Number of paddle wheel aerators
Number of spiral aerators
3000
30-60
4 aerators
(10 paddles each aerator)
1
3000
60-100
4 aerators
(10 paddles each aerator)
2
4.000 - 5.000
30 - 60
6 aerators
(10 paddles each aerator)
2
4.000 - 5.000
60 - 100
6 aerators
(10 paddles each aerator)
3 - 4


Setting up paddle wheel aeration system and the runtime must ensure the oxygen demand for shrimps in ponds, especially during the evening/nighttime/dawn, when dissolved oxygen levels decrease and are low of the day.

It is also needed to enhance the runtime for paddle wheel aerators or add on aeration system for shrimp, especially on prolonged hot or rainy days.

Source: Temporary process for safe brackish-water shrimp farming in areas affected by diseases in Vietnam. According to The Official Dispatch No. 10/TCTS-NTTS. January 6th, 2015. Vietnamese Directorate of Fisheries

Viet Linh 2015. Translated by Sonia Linh V.

1 comment:

  1. For 6acres pond, reactangular pond. How many paddle wheel aerators are required. We are doing polyculture, 5k Rohu, 1k Catla(Carp varity), 1k Grass Carp, 1k Milk fish, 1k Mrigal carp, 1k Common Carp and 2lakh Vannamei.

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