Fish pond water quality management directly affects the efficiency of fish farming. 

The main indicators to measure the quality of the fish pond are: pond water temperature, pH value, dissolved oxygen value and transparency. 

The test technology is introduced as follows:

Temperature test

Different fish have different requirements for water temperature. Silver carp, bighead carp, grass, carp, and bream are warm-water fishes, 

and the water temperature suitable for life is 20℃～30℃. Tilapia is a tropical fish, and the suitable water temperature is 25℃～34℃. In order to create the most suitable temperature environment for the fish, it is necessary to keep abreast of the temperature changes of the pool water. 

The most commonly used to monitor water temperature is a mercury thermometer, but only the surface water temperature can be measured. 

Both the water quality analyzer and the dissolved oxygen tester have a water temperature test function, and can measure the water temperature of different water layers.

PH test

The pH value of the pond water not only affects the growth and life of fish, but also affects the nutrients in the pond water. 

Therefore, people often use lime to adjust the pH value of the fish pond water. For warm-water fish such as silver carp, bighead carp, grass, common carp, and bream, it prefers alkaline water, and its suitable pH value is 7.5 to 8.5.

Dissolved oxygen test

The suitable dissolved oxygen value for general fish is more than 3 mg/liter. When the dissolved oxygen value in the water is less than 3 mg/liter, the fish stop eating and growing; when the dissolved oxygen value is less than 2 mg/liter, the fish will float; at 0.6 Death began at ~0.8 mg/L. 

In the past, most of the dissolved oxygen values were tested using chemical methods, that is, the sulfonation method. Although this method has high accuracy,

 it is troublesome and difficult, and it is difficult for ordinary fish farmers to grasp. In recent years, many electronic instruments for measuring dissolved oxygen values 

have been put on the market, such as water quality analyzers and dissolved oxygen testers. These instruments have a dedicated probe. Just put the probe in the water 

and set the switch to the oxygen measurement position. After about 1 to 2 minutes, the pointer on the meter head will indicate the dissolved oxygen value in the water.

Transparency test

The so-called transparency is the degree to which sunlight penetrates into the water. Transparency is directly related to the color of the water, and the color of the water marks the leanness of the water and the amount of plankton in the water.

To determine the transparency, you can make a black-and-white disc by yourself: cut a disc with a diameter of 20 cm from a thin iron sheet, punch a small hole in the center of the disc with iron nails, and paint the disc in black and white with black and white paint , Thread a string in the center of the disc and mark the ascent on the rope. Immerse the black and white disc in the water of the fish pond until the surface of the disc is just out of sight. At this time, the marked value of the length of the rope on the water surface is the transparency of the pond water. 

If the transparency is greater than 35 cm, it means that the pond water is too thin and should be topdressed, and more feed can be added; if the transparency is less than 25 cm, it means that the pond water is too fat.