Yieryi Professional Pool Salt Tester is a fourinone tester for salt, TDS, EC, S.G and temperature, suitable for pools, aquariums and spas. It connects with the Tuya app for realtime readings, historical data, and easy sharing. Key benefits Maintain correct salt levels: For saltwater pools, target 2700–3400 ppm to keep water clean and balanced. Four measurements in one device: salt, TDS, EC, S.G and temperature with a titanium electrode for sensitivity and an LCD display for clear results. Smart monitoring: Realtime data on the Tuya app, with history records and simple result sharing to track trends. Reliable performance: Titanium electrode delivers fast, accurate readings. For results in cold environments, immerse the tester in the liquid and wait for a stable reading. Use scenarios Saltwater pool care: regularly check salinity and adjust the salt generator or water replacement as needed. Aquarium maintenance: monitor salinity and water quality to suit fish species and prevent stress. Spa balancing: keep conductivity and salinity within comfortable ranges for guests. Notes For accuracy, follow immersion guidance in low temperatures and read the LCD clearly.