The water quality monitoring project for ornamental fish in Baodi, Tianjin

This project is a collaboration from Taiwan. The biggest challenge of this project lies in the large number and long distance of monitoring points. There are a total of 45 monitoring points, and each point needs to measure three parameters (pH, dissolved oxygen and temperature). Transmitting the data to the central control room using the traditional 4-20mA would waste a lot of signal lines and be unstable.In this case, I proposed to change the original 4-20mA output of the instrument to RS485. In this way, the 45 monitoring points can be connected in series and finally transmitted to the central control room through one data bus. This not only reduces the number of signal lines but also brings convenience to the on-site installation and commissioning.
In addition, dissolved oxygen is an extremely important indicator in the aquaculture industry. In the breeding room, the control range of dissolved oxygen can be set according to the dissolved oxygen range that the farbred objects are suitable for. The computer controls the chip to automatically turn on and off the aerator within the set control range of dissolved oxygen based on the data collected by the dissolved oxygen sensor. Reasonable use and configuration of the aerator not only save electricity but also reduce mechanical wear. It also achieves the greatest efficiency with the least input.
Computer management software can analyze the disease pattern of the money fish based on the range of dissolved oxygen changes, issue disease warnings in a timely manner, and prevent the occurrence of diseases. Analyze the degree of deterioration of water quality based on the changes in dissolved oxygen, and take timely measures for treatment, such as sewage discharge, water replacement, adding aerators, and digestion bacteria, etc.For the selection of dissolved oxygen electrodes, I gave up the expensive fluorescence dissolved oxygen electrode and chose the traditional polarographic dissolved oxygen electrode. The polarographic dissolved oxygen electrode not only measures accurately but also has a low maintenance cost. It only requires regular addition of electrolyte and replacement of membrane sleeves.
The pH value of water quality is also quite important. Based on the changes in pH value, the deterioration of water quality and the generation of harmful substances such as ammonia nitrogen, sulfides, and nitrites, as well as the degree of decomposition and oxidation of organic matter like residual feed, are analyzed. Through the alarm system, a water quality analysis report is submitted and warning information is sent. So as to take various measures in time.
For the installation method of the pH electrode, I chose the submerged installation, which is convenient for users to clean the electrode in the future and has received unanimous praise from users. This set of solutions has helped the client save a significant amount of costs, achieving an automated breeding base integrating monitoring and control, and has become a model in the prosperity fish breeding industry.