Natural fertilizer such as cow/chicken manure, green manure and compost and chemical fertilizer can be used to be abundant of natural food and to reduce the supplementary feed.
Fertilizers promote the growth of phytoplankton and production of natural food.
15-20 kg of urea and 7.5-10 kg of TSP per ac can be used for normal primary production.
TSP must be soaked overnight and at the next morning, 10-11 am, mix urea, water and soaked TSP, and then broadcast them evenly to grow plankton on the surface.
Since fertilizers, especially TSP, take time to dissolve into water, should avoid direct application without soaking in water.
Fertilization should be used weekly or biweekly throughout the cultural period so that natural food can be maintained.
Points to be aware in fertilizer application
Aware not to over fertilize.
Avoid fertilizer application if the pond water appears turbid.
Avoid fertilizing on extremely hot days if the water is shallow.
Avoid applying fertilizer if it is raining or cloudy.
Avoid fertilizing 2-3 days before and after harvesting.
Ensure well dissolving of fertilizer before application.
If the pond water color is not the desired color, light green, stop fertilization application.
In the winter season, the amount of fertilizer should be half or less than the amount applied in summer.