AQQA Submersible Aquarium Heater 500W for 55-130 Gallon Fish Tank Quartz Glass with External Controller for Betta Tank Koi Pond Saltwater & Freshwater (AQ197-500W for 55-130Gal)

Fast Heating with Durable & Safe Design – The aquarium heater is made of explosion-resistant quartz glass and high-temperature resistant nickel-chromium for quick heat transfer and reliable performance in both saltwater and freshwater tanks. Dual sensor probes provide more accurate temperature monitoring, while the PC plastic protective cover prevents direct contact, ensuring your fish stay safe from burns.

Easy Operation with External Controller – The submersible fish tank heater comes with a convenient external controller for easy and precise temperature adjustment. Press the “SET” button to enter the temperature setting mode, and each press increases the set temperature by 1°F/1°C within the 59°F–93°F (15°C–34°C) range. Press and hold for 5 seconds to switch between Fahrenheit and Celsius.

Overheating & Dry-Run Protection – The fish tank heater will automatically shut off when the water temp reaches set temp. If the temp rises rapidly 3°F/3°C higher than set temp , the heater will stop heating immediately and a flashing alert will appear on the controller. When the heating rod is exposed more than 1 inch above water, an “E0” error code appears and heating stops. The protection systerm prevents overheating and dry burn, keeping your fish safe

Intelligent Automatic Heating – The AQQA aquarium heater adopts automatic thermostatic control. It stops heating when the water reaches the set temperature and automatically restarts when the temperature drops 2°C/°F below the set point. The memory function retains your settings after a power outage, making it more convenient to unplug the power cord for water changes.

Usage Instructions – Always fully submerge the aquarium heater in water before plugging it in, and ensure proper water circulation in the tank. After turning it off, allow the heater to cool in the water for 15–30 minutes to prevent residual heat from damaging the cover. Following these safety tips helps extend the lifespan of your fish heater. For any issues, feel free to contact us