Review on Adjustable LED Digital Temperature Display Submersible Fish Tank Heater 🐢 with Protective Guard - ideal for Turtle, Betta Fish, and Aquariums by Samiran Pusarla

I have 3 of these heaters in 3 different tanks: 1 20 gal, 1 28 gal and 1 30 gal. All keep the temperature very well with an accuracy of 1 degree. Settings (I use a separate digital thermometer in all my tanks to check heater temp). The only reason I didn't give it 5 stars is because one of my heaters had algae growth in the plastic case that displays the temperature making it impossible to read the settings. I've tried cleaning it, but it's definitely inside, so the device isn't waterproof as advertised. Note, however, that even with algae growth inside the housing, the heater will still perfectly keep the temperature in the aquarium at the desired level, which I turned on.