However, in practice, the dissolved oxygen level in pond water is sometimes so low that it fails to meet the needs of fish for normal growth and maintenance of basic metabolism. This leads to reduced activity, poor feeding ability, and slow growth in farmed fish, resulting in feed wastage and a high feed conversion ratio. Moreover, organic matter decomposed by oxygen cannot be fully broken down, further deteriorating water quality and making farmed fish more susceptible to diseases. Additionally, low dissolved oxygen levels can cause fish to surface for air, a condition known as "oxygen depletion," which may ultimately lead to the death of the entire fish pond and substantial economic losses. A straightforward way to increase dissolved oxygen in water is to use an aeration machine for fish ponds.

　　However, in practice, the dissolved oxygen level in pond water sometimes drops to a dangerously low level, failing to meet the needs of fish for normal growth and maintenance of basic metabolism. This leads to reduced activity, poor feeding ability, and slow growth in farmed fish, resulting in wasted feed, high feed conversion ratios, and an inability of oxygen-decomposed organic matter to break down properly. Consequently, water quality deteriorates, making farmed fish more susceptible to diseases. Moreover, low dissolved oxygen levels can cause fish to surface in search of oxygen, leading to mass mortality in the entire pond and causing significant economic losses. A straightforward way to increase dissolved oxygen in water is to use pond aerators. To ensure that aerators truly become productivity-enhancing tools, it’s essential to use them appropriately. The specific methods are as follows:

　　1: Optional Installation Principles

　　Fully meet the dissolved oxygen requirements for the normal growth of fish and prevent oxygen depletion in the pond, which could lead to fish suffocating and floating to the surface. It is essential to both prevent water quality deterioration and the occurrence of diseases, as well as to reduce operational costs. Therefore, when selecting an aeration device for fish ponds, one should take into account factors such as the type of aquaculture species being raised, water depth, pond area, pond shape, planned production volume, operating costs, and efficiency, in order to choose the appropriate type and power rating of aeration equipment. The aeration device should be installed either at the center of the pond or on the windward side.

　　2: Instructions for Use

　　The start-up time and operating duration of the aerator should be determined based on factors such as season, weather, water quality, water temperature, cultured species, fish activity and rearing conditions, stocking density, fertilization practices, and feeding regimes, as detailed below:

　　1. Summer and autumn are the peak seasons for fish growth. During the day, water temperatures are high, fish become more active, and their oxygen consumption increases, making them prone to oxygen depletion. At dawn, you can appropriately turn on the aerator to increase dissolved oxygen levels. If the weather is hot, the aeration period should be slightly extended. Do not turn on the aerator after sunrise.

　　2. During normal aquaculture practices, on sunny days, turn on the aerator for 1–2 hours around noon to fully harness its oxygenation, mixing, and aeration functions. This promotes the oxidation and decomposition of harmful substances in the water, helps remove harmful gases, increases dissolved oxygen levels, improves water quality, and prevents fish from surfacing for air (floating heads). However, be careful not to turn it on at night. On cloudy or rainy days, phytoplankton photosynthesis is weaker, making oxygen depletion more likely. Therefore, the aerator should be started earlier in the late evening, and its operating time should be longer. During heavy rainfall, turn on the aerator at night to promptly replenish oxygen and prevent fish from floating heads. Avoid starting the aerator at noon on rainy days, as this can easily trigger fish floating heads.

　　3. When the stocking density is relatively high and fish grow rapidly, the initiation period should be appropriately extended. If the feed dosage is increased and the water quality becomes overly rich in nutrients, a combined approach—starting at noon on sunny days and also in the early morning—should be adopted to boost dissolved oxygen levels in the water and prevent fish from surfacing for air.

　　4. During pond patrols, if you notice abnormal fish activity, reduced feeding, or fish floating at the surface, you should promptly start the aerator until the fish return to normal behavior. When there is a significant temperature difference, turn on the aerator promptly.

　　5. During the aquaculture process, the start-up and operation times should be flexibly controlled based on specific conditions and the patterns of dissolved oxygen in the water body (daily and nocturnal variations, vertical variations, horizontal variations, and seasonal changes), ensuring rational utilization, cost savings, and increased productivity and efficiency.

　　As can be seen from this, properly using an aerator to increase dissolved oxygen levels not only promotes the decomposition of organic matter, improves water quality, and safeguards the ecological aquatic environment upon which fish depend for survival, but also reduces disease incidence and accelerates growth, truly making it a machine for boosting production.