Fish farmers should know how to build a suitable fish pond to get better benefits. There are seven aspects to improving the quality of fish ponds.
Choose a place with sufficient water, good water quality, and convenient transportation and power supply to build a fish pond. This not only facilitates injection and drainage but also facilitates the transportation and sale of fingerlings, fish feeds, and adults.
Ponds should have good water conditions for frequent water changes. Due to the high density of fish culture in ponds, the large amount of fish feed pellets and fertilization, the dissolved oxygen in the pond water is often in short supply, and the water quality is easily deteriorated, resulting in serious fish plankton and a large number of deaths. Although the existing aerators can prevent fish from floating, they cannot fundamentally improve the water quality and are not conducive to the growth of fish in the long run.
The best source of pond water is unpolluted river and lake water. This water has high dissolved oxygen and good water quality, which is suitable for fish growth. Therefore, fish ponds are best located near rivers or lakes. Well water can be used as a water source for fish farming, but its temperature and dissolved oxygen are low. When using well water, it should flow through a long channel or set up a sunbath, and set up a water receiving plate below the water inlet. Water splashes on the receiving plate and flows into the pond, raising the water temperature and dissolved oxygen. The wastewater discharged by industrial and mining enterprises often contains substances harmful to fish, and can only be used as water for fish farming after analysis and trial breeding.
Ponds for raising domestic fish are larger in size. The area is large, the fish activity range is wide, and it is greatly affected by the wind. Wind can not only increase the amount of dissolved oxygen, but also mix the upper and lower layers of the pond and improve the dissolved oxygen conditions of the lower water. However, the area should not be too large, the fish feed is not easy to mix, the water quality is not easy to control, and the management is inconvenient.
Ponds need to have a certain depth and water storage in order to increase stocking and increase production. The water in the pool is deep, the water storage capacity is large, and the water quality is relatively stable, which is conducive to the growth of fish. But the deeper the pond is, the better. If the pool water is too deep, the lower water has poor lighting conditions, low dissolved oxygen, and the decomposition of organic matter consumes a lot of oxygen, which is likely to cause frequent hypoxia in the lower water. Therefore, the pond water level should be maintained at 2.0m to 2.5m.
Ponds have the best soil quality, followed by stickiness and the worst sand. In fish ponds that have been cultured for 1-2 years, the accumulated bait, fish manure and biological sediments are mixed to form sludge, which replaces the original soil. If there is too much sludge, the oxidative decomposition of the organic matter contained in it will consume a lot of oxygen, which is easy to cause hypoxia. Moreover, the anaerobic fermentation of organic matter will produce ammonia, hydrogen sulfide and other harmful substances after hypoxia, which affects the survival and growth of fish. Usually, when stocking fingerlings, 5 cm thick silt should be left at the bottom of the pond, which has a great effect on supplementing the nutrients in the water and maintaining and regulating the fertility of the water body.
The best fish ponds are rectangular ponds that are long from east to west and wide from north to south. The advantages of this pool shape are that the ridges of the pool are less shaded, and the surface sunshine time is long, which is conducive to the photosynthesis of phytoplankton. The pool water can naturally increase the oxygen in the dynamic and reduce the floating head of the fish. Rectangular pools have an aspect ratio of 5:3. This kind of rectangle is not only beautiful in appearance, but also conducive to feeding management and net pulling operation, and it is also easy to cause pool water circulation when adding water. There should be no tall trees and houses around the pond so as not to block the sun and wind.
The best shape for the bottom of a fish pond is the “turtle back”. The pond is high in the middle and slopes on all sides. The junction with the pool slope is the deepest, forming a shallow ditch (commonly known as the pool). In this way, the annual drainage and fishing are very convenient, and the distance for transporting fish is short. In addition, the pool mud is mainly deposited in the deepest pool at the bottom of the pool. The excess mud can be easily removed and repaired nearby, and the labor intensity is relatively small. When pulling the net with this type of pool structure, just use the fishing rod to press the lower part into the tank groove, so that the whole part is pulled tight and close to the bottom of the pool, and the fish is not easy to escape from the lower part. Greatly increase the catch rate of low-grade fish.