2) Prawn’s adapting range to dissolved oxygen

　2. The change of dissolved oxygen
The dissolved oxygen in the pond is influenced by sunshine, wind power, water’s quality and other factors.
1) The photosynthesis increases, so does the hydrogen and oxygen dissolved by water molecules.
2) The temperature is high. The dissolved oxygen in water will decrease gradually with the increase of temperature; besides, the much-consumed oxygen by aquatic animals and other living things in high temperature is another important reason.
3) The raising density is too high. The respiratory function of living things increases, so dose its consumed oxygen.
4) Organism has oxidation. If there is sulfur and nitrite in water, it will has oxidation and consume a lot of dissolved oxygen.
5) Organism has resolving function. The more organisms, the more active bacteria. This process will consume much oxygen, so it is easy to be short of oxygen.
Though dissolved oxygen has some changing rules, there is no way to judge the amount in pond correctly just depending to experience. Intelligent oxygen-rising tester and controller can solve this problem.
　3. Testing and control of oxygen
At present, aquiculture mainly depends on oxygen-increasing machine to solve the problem. Since it is hard to judge the amount of dissolved oxygen correctly, manual control oxygen-increasing machine still has some kind of blindness, which is hard to reach the aim of having the suitable amount of oxygen and saving the electricity power. Besides, the shortage of oxygen always happens. In order to realize aquatic animals’ keepers dream of stable and high production, since 1997 when our company started to produce dissolved oxygen electrode, we had paid much attention to the research of testing and control technology on dissolved oxygen in the poll as well as to the development of new products. Relying on East China University of Science and Technology, Shanghai Fisheries University, Xiamen University, Xiamen Fishery Bureau and agriculture Science College’s doctor hierophants, professors, researchers, high-level engineers and doctors, we receive high-level professional instructions, combining customer’s practical needs. We made the research and developed the most advanced aquiculture water’s quality testing and control products, among which are the most representational poll’s oxygen-increasing machine, intelligent oxygen- increasing testing and control machine (including view control, sound control, wire control and automatic control), pool’s absorber, probing machine with good quality and low price. They meet all the customers’ demand, which is the precious result of integration of biology, mechanics, biological passing-feeling technology, theca technology, biological electricity technology and information passing technology.