Review on BOEESPAT Submersible Aquarium Heater 100W/200W/300W/500W with Anti Scald Protector, Thermometer Included - Ideal for Marine Saltwater and Freshwater Fish Tanks by Elizabeth Thornton

I needed a heater that could be adjusted so I could raise or lower the temperature in my aquarium to help fight disease. When I installed the new heater, the aquarium was 78 degrees. The new heater was set to 77 degrees. After 2 hours the temperature in the tank was 81.9 degrees. I lowered the temp a few degrees and the reading went up to 81. I lowered it to the setting shown in the photo, about 74 or 75 degrees, and it ended up going down to 77.9. What's the benefit? I gave it two stars simply because it has a guard that protects the fish from scalding and a separate thermometer that is easy to read, although the reading shows how big the temperature difference is between the setting on the heater and the reading on the heater is. Thermometer.