Do I still need a separate aquarium thermometer if my heater has a thermostat or digital display?
Yes, a separate thermometer helps check the actual water temperature and catch small differences between a heater's setting and what the tank is holding. Because stable, accurate temperatures are so important for fish health, pairing a heater with a simple thermometer makes it easier to watch and fine-tune as room conditions change.
What is the difference between an aquarium heater and a pond or stock-tank de-icer, and when should I use each?
Aquarium heaters are made to keep a consistent target temperature inside a tank, which supports steady, stress-free conditions for fish. Pond and stock-tank de-icers are built for outdoor or unheated setups and focus on preventing ice buildup rather than holding a precise tropical range. Choose an aquarium heater for maintaining a set temperature indoors and a de-icer for cold-weather protection in ponds or utility tanks.