Review on 🐠 PERSUPER Aquarium Heater 100W/200W: Submersible Fish Tank Heater with Adjustable Thermostat 68 to 94°F, LED Display - Fast Heating Water Temperature Controller for 10-40 Gallons by Darcy Thorson

I don't know who writes these reviews but this is an unreliable product. I received one and it stopped working a few days after putting it into service. It worked fine, and in the morning I got up and the display flashes E1, which according to the instructions means that the low water sensor is not submerged, but was submerged. Nothing I've done has fixed the problem. Thinking it was just one of those random glitches I returned it to exchange for another. Put the new one into operation, and in three days it will do the same thing as the previous one. This is not a reliable product.