Guide to Selection and LoRaWAN Deployment of Water Quality Sensors in Tilapia Farms

Selecting and deploying water quality sensors in tilapia farms is crucial for ensuring the healthy growth of tilapia and improving aquaculture efficiency. Below are recommendations on how to select water quality sensors and deploy LoRaWAN water quality sensors:

1. Selection of Water Quality Sensors

Consider the growth needs of tilapia: Tilapia have relatively strict requirements for water quality. Key parameters to monitor include dissolved oxygen, pH value, temperature, and ammonia nitrogen. For example, dissolved oxygen should be maintained at 5-8mg/L, pH value between 6.5-8.5, temperature kept at 26-30℃, and ammonia nitrogen concentration below 0.5mg/L. Therefore, sensors that can accurately measure these parameters should be selected.

Measurement accuracy and stability: Choose sensors with appropriate accuracy based on aquaculture needs. For instance, high-precision devices (with pH measurement error ≤ ±0.05 and dissolved oxygen resolution of 0.01mg/L) are required for drinking water safety monitoring, while medium-precision sensors are sufficient for industrial process control scenarios. Meanwhile, prioritize sensors with automatic calibration functions to ensure long-term stable operation and reduce manual maintenance costs.

Environmental adaptability: Tilapia farming environments are diverse, so sensors must have good environmental adaptability. For example, in pond aquaculture, sensors should have an IP68 protection rating to prevent water and dust ingress. In coastal areas or mariculture, select sensors made of corrosion-resistant 316L stainless steel to effectively resist erosion from chloride ions in seawater.

Multi-parameter integration and expandability: To comprehensively monitor water quality, consider multi-parameter integrated sensors. For example, the chip-level multi-parameter water quality sensors from Guangdong Xinyue Technology can simultaneously monitor temperature, dissolved oxygen, pH, and electrical conductivity, reducing the number of sensors and facilitating centralized data processing. Additionally, select sensor platforms that support modular expansion to adapt to future changes in monitoring needs.

Cost-effectiveness: Consider both the initial purchase cost and operation and maintenance costs of sensors. For large-scale farms, medium-precision sensors with high cost-effectiveness can be selected to meet monitoring needs while reducing equipment investment. Meanwhile, prioritize maintenance-free or low-maintenance sensors (such as those with automatic cleaning functions) to reduce the frequency of manual cleaning and lower operation and maintenance costs.

2. Deployment of LoRaWAN Water Quality Sensors

Determine monitoring points: Arrange sensors reasonably based on the size and shape of the aquaculture pond. For larger ponds (e.g., over 5 mu), it is recommended to install 2-3 sensors in different locations (such as the shore and central area) to ensure the comprehensiveness and accuracy of water quality data. At the same time, avoid interference areas such as feeding areas, feces accumulation areas, sediment areas, and areas near aerators or water pumps. Choose locations with uniform water circulation and slow water flow, such as areas more than 10m away from feeding areas, the middle layer of the water body (0.5-1m deep in the pond), and areas more than 3m away from aerators.

Selection of installation methods:

Pond aquaculture: Buoy-type installation can be adopted. Fix the sensor on a buoy bracket, add a counterweight at the bottom, fix the buoy to the shore pile with a rope (reserving allowance for water level fluctuations), and fix the sensor cable along the rope with proper waterproof treatment. Bracket-type installation is also an option: insert a PVC or stainless steel bracket into the pond bottom, fix the sensor on the horizontal bar of the bracket, and ensure the sensitive membrane does not touch the bracket and is far from the pond bottom sediment.

Industrial recirculating aquaculture: Pipeline-type installation can be selected. Install a tee in the stable section of the core circulation pipeline (with a diameter ≥ 50mm), connect the sensor to the tee through a threaded interface, and face the sensitive membrane toward the water flow direction. Submerged installation is also feasible: drill a hole in the pond wall, insert the sensor from the outside to the middle layer of the water body, keep the sensor head at least 0.5m away from the pond wall, and install a protective net.

LoRaWAN network construction:

Underwater part: Sensors are connected to underwater sub-control nodes via shielded twisted pairs, with interface standards such as industrial-grade RS-485 or CAN bus. Underwater sub-control nodes are responsible for data aggregation and preprocessing (e.g., CRC verification, data compression) to reduce the LoRa transmission load.

Surface part: The surface LoRa gateway uses LoRa modules (such as SX1276/SX1262) to achieve wireless communication with underwater sub-control nodes and transmit data to the cloud server. The LoRa gateway can be powered by solar energy (e.g., 50W panel + 20Ah lithium battery) to ensure normal operation in environments without power supply or with unstable power. Meanwhile, a dual-link backup can be set up: the main link uses LoRa transmission, and the backup link uses 4G DTU to ensure real-time transmission of key data.

Commissioning and maintenance: After installation, commission the sensors (including power-on preheating and on-site calibration) to ensure data accuracy. Meanwhile, establish a regular maintenance mechanism: clean the sensor probes monthly, check the voltage of the power supply module, and perform full-parameter calibration quarterly to ensure long-term stable operation of the sensors. In addition, real-time monitor the equipment status through a cloud management platform to promptly detect and handle issues such as data interruption or abnormal fluctuations.