The determinants and changing rules of pH value
1. Determinant of pH value. There are many factors that determine the pH value, but the most important is the balance system of free carbon dioxide and carbonate in water, as well as the content of organic matter in water and its decomposition conditions. The balance system of carbon dioxide and carbonate changes according to the hardness of the water and the increase or decrease of carbon dioxide. The increase or decrease of carbon dioxide is determined by the relative strength of biological respiration in water, oxidation of organic matter and photosynthesis of plants.
2. The change law of ph value with temperature. Under normal circumstances, the ph value begins to rise gradually at sunrise and reaches the maximum value around 4:30-5:30 pm, then begins to decline until it reaches the minimum value before sunrise the next day, and so on. The normal daily variation range of ph value 1 to 2, if it exceeds this range, the water body is abnormal. The diurnal variation of pH value is because phytoplankton needs to absorb carbon dioxide CO2 for photosynthesis, which causes the change of carbon dioxide CO2 in water body, and the difference of CO2 content affects the diurnal variation of pH value. Mastering the diurnal variation of pH value has important guiding significance and utilization value for breeding management.
3. The ph value is used as the actual value of the water quality standard. If you see that the ph value of a fish farming water body is low and there is no special external pollution, you can judge that the water body may have low hardness, excessive humus, high dissolved oxygen and carbon dioxide CO2, and insufficient dissolved oxygen. The photosynthesis of water plants is not strong or the density of fish is too high and microorganisms are inhibited, and the metabolism of the entire material metabolism system is slow. If the ph value is too high, it may also be that the hardness is not enough, and the plant reproduction is too vigorous, the photosynthesis is too strong or the humus in the pond is insufficient.
