Review on 🐠 AQQA Small Aquarium Heater: Efficient Submersible Fish Tank Heater with Intelligent LED Display and External Controller - Perfect for Betta Fish and Turtle Tanks by Darla Wilmoth

Update: Not great, at least for beta versions. Side slots provide ample room for small fish to enter and cook. There should be some kind of net over them to keep the fish away. This heater maintains a constant water temperature with a clear display. It's easy to change the setting from outside the tank. Not having to put your hand in the water with the fish like many others is a real plus.