Review on Submersible Energy Efficient Controller Thermostat Thermometer by Angela Tarpley

We received a dwarf fish and had to rush to buy all the supplies. Strangely, the pet store didn't mention that we needed a heater and our little one didn't look happy at all. We ordered this heater for our 3 gallon tank. It's set to 77 degrees (I don't think there's a way to change that setting) and it works great. My Betta is much happier now too. One thing I noticed is that the heater works a lot at night when it's cold, and certainly not as much, if at all, during the day when the room temperature gets warmer (we live in Florida and it's winter). However, since the water preheats to 77 degrees at night, my aquarium also heats up during the day. I found my tank at 84. Betta still seems happy, but I have a feeling this is probably the limit. I would be concerned that a smaller tank could experience even greater temperature swings in similar weather conditions. I'd advise being careful with a smaller tank than mine, but for over 3 gallons this is perfect for you.