When should shrimp ponds be fertilized to enrich the water? The most economical method explained in one go

SummaryFertilization timing: the fertilization time is about 20 days before stocking the fry. Fertilization method: for general muddy and sandy-muddy ponds, using inorganic fertilizer works better, while sandy-bottom, high-level ponds, and ponds lined with plastic film are more difficult to fertilize, and a combined method of inorganic and organic fertilizers can be used, with relatively good results; at the same time, the whole water body needs to be disinfected. 2-3 days after disinfection, water can be let in filtered through 80-mesh mesh gauze, to prevent fish and shrimp larvae, or eggs and large zooplankton, from entering the pond.

I. Fertilization timing

1. The fertilization time is about 20 days before stocking the fry. Because during the fertilization process many physical and chemical factors in the pond are changing drastically, among which the more obvious one is the change in pH value, showing a “∧” pattern of change; in the early stage the pH value keeps increasing, and can sometimes reach 10.

2. After 15 days, it will gradually decline, and at around 20 days the pH value can be around 8.5, which is relatively suitable for shrimp growth. At the same time, at this point the water color, transparency, and plankton biomass are all in a relatively good state, which is relatively suitable for stocking fry, so the fertilization time is suitably arranged at about 20 days before stocking the fry.

II. Fertilization method

1. Which specific substance to use for fertilization needs to be determined according to the bottom conditions of the pond; for general muddy and sandy-muddy ponds, using inorganic fertilizer works better, while sandy-bottom, high-level ponds, and ponds lined with plastic film are more difficult to fertilize, and a combined method of inorganic and organic fertilizers can be used, with relatively good results.

2. Most shrimp farmers report that after fertilizing shrimp ponds, some water cannot be fertilized; if it does get fertilized, it quickly becomes clear again, over and over, and it is very difficult to cultivate algae. It is understood that many shrimp farmers, to prevent shrimp disease, have adopted a whole-water-body disinfection method: however deep the aquaculture water body is, disinfection is carried out with a water body of that depth.

3. Generally, the method of filling the pond full of water is used to disinfect the pond and the water body, and harmful organisms and various pathogens will be killed, but various beneficial organisms in the pond, including various zooplankton and plants, will also be killed. After these organisms are killed, the water body will become transparent, and the pond bottom can be seen clearly.

4. Therefore, in such a water environment, there are already no algae seeds, which is the reason why water is difficult to fertilize after fertilization. Because this kind of water body has few algae species, even if a certain water color and transparency are cultivated, they cannot last very long, so the water color changes over and over and it is very difficult to fertilize the water. The correct pond disinfection method is to let in about 10 cm of water, generally based on just submerging the pond bottom surface. This kind of water body can not only kill bacteria and viruses at the pond bottom, but also kill harmful organisms, while at the same time saving costs.

5. 2-3 days after finishing pond disinfection, water can be let in filtered through 80-mesh mesh gauze, to prevent fish and shrimp larvae, or eggs and large zooplankton, from entering the pond. At this time the water let in will bring in a large amount of plankton, that is, zooplankton and phytoplankton. These phytoplankton will absorb nutrient salts when fertilizer is applied, and after waiting 24-48 hours, a good water color and transparency can be cultivated.

6. Phytoplankton reproduce rapidly and can provide feed for zooplankton, prompting rapid reproduction and making it easy to form a good ecological environment. At this time, the newly stocked shrimp fry can grow robustly in a good environment.