2.1.4. Managing water color

– Create and control water color in ponds helps develop micro-plankton, stability of water environment, and creates a favorable environment to limit shocks in shrimp and improve survival rate.

– The use of biological products from reputable companies with clear sources (such as TA-GOLD, Rhodo powder, Pro BCS, etc.), incubated with rice bran, molasses, soy flour, before being released in ponds can control water color.

– Combined with using lime Dolomite + CaCO3 with a dose of 20 kg/1000m3.

Note:

+ Do not use inorganic fertilizers to create color for the water.

+ Check and adjust water environmental factors in pond before stocking:

Table 4. Quality of water supplied to ponds and water in ponds.

No.	Parameter	Unit	Allowed values
1	Dissolved oxygen	mg/l	≥3,5
2	pH		7÷9, with fluctuation during a day no more than 0,5
3	Salinity	per mile	5÷35
4	Alkalinity	mg/l	60÷180
5	Turbidity	cm	20÷50
6	NH3	mg/l	<0,3
7	H2S	mg/l	<0,05
8	Temperature	degree Celsius	18÷33

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.