Principle of Aquaculture (1+1)

Procedure

1. Initially predatory fishes present in the ponds are harvested by netting.

2. If possible, drain the water completely and disinfect the pond bottom with suitable disinfectant.

3. However, where it is not possible, the pond should be treated with fish poison at the rate given in the table.

Calculation of dose

The required quantity of poison can be calculated using the following formulae.

For rectangular ponds:

= Required amount of poison in kg.

For circular ponds:

1. = Required amount of poison in kg

Table 1. Recommended doses of fish poison
Poison	Dose (kg/ha/m)
Bleaching powder	350 – 500
Mohua oil cake	2 500
Anhydrous ammonia	20 – 30
Powdered seed of Croton tiqlium	30 – 50
Root powder of Milletia pachycarpa	40 – 50
Seed powder of Milletia piecidia	40 – 50
Seed powder of Barrinqtonia acutanqula	150
Seed meal of tamarind (Tamarindus indica)	1 750 –2 000
Tea seed cake (Camellia sinensis) *	750