Review on 🐠 Hygger 500W 800W Submersible Fish Tank Water Heater with LED Digital Temperature Controller - Ideal for Saltwater and Freshwater Aquariums, Fast Heating for 60~180 Gallon Tanks by Lauren Yazzie

The 800w heater easily handles my 125 gallon aquarium. I ordered a replacement about 6 months later as the original was not temperature controllable and the new one was sent free of charge. The new one is fine. Note: This heater, like everything I've had, measures the temperature of the water next to the heater. Therefore you have to set the temperature a few degrees warmer than you actually want the aquarium to be. You must have a way of measuring the temperature of the water in the part of the tank that is not near the heater.