Review on 🐠 Penn-Plax 75-Watt Fully Submersible Aquarium Heater: Precise 1 Degree Accuracy - Ideal for Up to 15 Gallon Tanks by Guadalupe Culii

Heats water. But you'd be better off hooking it up to a heater controller or closely monitoring your tank temperature with an accurate thermometer and adjusting that heater accordingly. I keep my tanks at 78°F. I set this heater to what should have been 78°F. For the first few days the temperature in my 15 gallon tank hovered around 73C, so I turned on the heater at half an orange bubbling every 12 hours until the temperature in the aquarium reached 78C. With the heating switched on, it then jumped to 82°. I turned the heater thermostat back on. It is currently set to 79° but my tank is 76.6 and the heater is not on. I have Aqueon heaters in my 3.5 gallon, 10 gallon, 20 gallon, and 36 gallon tanks with no problems. I ordered Eheim for this tank. I will only be keeping this heater as a spare because shipping is half the price of the original item.