Review on 🐠 HITOP 500W Aquarium Heater: Submersible Fish Tank Heater with Temperature Display for 100-200 Gallon Tanks by Stephanie Fields

Bought a heater for my 100 gallon tank and set the temp to 81 degrees. The thermometer on the unit will usually read 3-4 degrees below this, often with a "green" light indicating the temperature is normal. Now it flashes regularly and the temperature shows 88 degrees on the block, but wrong. The tank gets colder instead of warmer, so it doesn't work. Disconnected, waited, reconnected, same problem. Not worth the money I spent.