Review on 🐠 Aquatop Nano Aquarium Heater 15-Watt - Perfect for 2.6 to 4 Gallon Aquariums at 77°F! by Kris Wagner

A little bit about me. I have 3 reef tanks and needed a nano heater for my daughter's 4G betta tank. My typical Colbat heater is a bit larger than I like, so I decided to try different options. Needless to say, I'm coming back to something I know to be accurate and work at a specific temperature. I've had this in the tank for 3 days and it has changed from 77 to 80.4. The room he is in was somewhere between 65 and 77 degrees. I have a large 10g reef tank near this room and with another heater it was able to maintain the temperature at 77C. I just can't see how accurate the set temperature is, and don't even know if it's working. In a nutshell. If you are looking for an accurate heater and a reliable heater I would look elsewhere. This is my third preset "nano" heater and I was not impressed. Luckily there are no fish in the aquarium right now because he is riding his bike. Otherwise such a temperature fluctuation would be stressful for fish. Going back to what I know works, even if it's more than I like. I also have to admit that the cobalt nano heater does NOT work well in all situations as it is always on! This can cause the tank to overheat. The 25W Neo-Therm heater is a good option that I'll come back to.