Review on 🐠 Quartz Glass Submersible Heaters for CNZ Aquariums by Stacy Mendoza

Bought a 100w 2 pack because I wasn't sure how much heat I really need. My tank is 110 gallons and runs about 4 degrees Fahrenheit warmer than the room due to the pump and the slight heat. I didn't need more than enough heat from the heater because too much power would cause temperature swings and possibly overheating. THAT will kill the fish. All of these heaters (of all brands) are very slow to respond to temperature changes and this is the reason for most of the bad reviews all heaters get. If the heater is too powerful for a tank of this size, it will exceed the set temperature before shutting down. The generally recommended power is, in my opinion, too high for a home aquarium. But if it's not hot enough, make a very small adjustment and wait a few hours before adjusting again. A single 100W heater makes my tank 4 degrees warmer than before, which is what I wanted, and the set temperature on the dial is accurate. It is included in more than half of the cases. In winter when the room is cooler I may need a second heater. In any case, two 100W heaters are better than one 200W heater because the larger surface area for heat transfer minimizes temperature fluctuations.