Review on Tetra HT Submersible Aquarium Heater: Efficiently Regulate Temperature with Electronic Thermostat by Abbie Garcia

MONITOR THE TEMPERATURE IN YOUR TANK CAREFULLY. Either buy an alarm if it gets too hot or check the thermostat more often. I have these Heater for about nine months and "I've used it in a 10 gallon tank. It's been working GREAT to date. It broke one night and heated my tank to OVER 110 Fahrenheit. and three dead snails boiled alive. It was heartbreaking. There's a fatal flaw in these heaters." They're cheap and when they work, they work great, but you're taking a risk if you buy one of these for your tank.