Review on 🐠 Penn-Plax 75-Watt Fully Submersible Aquarium Heater: Precise 1 Degree Accuracy - Ideal for Up to 15 Gallon Tanks by Renee Hackbarth

I bought this heater about 2.5 weeks ago and overall I think it's a great heater for the money. This is one of the few heaters I've seen on Amazon that didn't "cook" the fish. When I first received it, it was slightly larger than expected, but that's not a big issue for me. I have this in a 3 gallon aquarium for my cockatiel and it doesn't take up too much space. I positioned him sideways on the back of his tank in the middle. I've had a rooster since January and to be honest I never bought a heater for it until I bought this one so at first I was hesitant to even set it to 80 degrees. I set it to 76 degrees at first just to keep it from too much of a temperature shock (it used to be about 72 degrees in the aquarium which I know isn't good for a betta). I kept it at 76 for the first few hours, then turned the dial down to 79. I know bettas need water between 76 and 83 degrees. The thermometer itself heats up the tank perfectly and turns on and off to adjust if needed. Last week or so I noticed that my thermometer is set at 79 and I have a digital thermometer that I attach to the outside of the tank and it reads about 77.7 degrees. In my opinion this is much better than overheating the thermometer and killing the fish. Right now I have it set to 81 and my digital thermometer reads around 79.8 and will fluctuate between 79.8 and 78.6. For me it is perfect for my fish. I could probably bump it up to 82 if I wanted to and it would level out at around 79.9-81.5, but I haven't done that yet. All in all I think this is a great heater. It definitely won't overheat your fish. Temperature settings on the thermometer range from 68-89 degrees. I would recommend starting with a lower temperature than necessary just to gauge how well the thermometer is working in your tank. It's a little different, maybe 1.5-2 degrees from what you set, but I'd just grab a digital thermometer that sticks to the side of your tank to check the temp. I will definitely try this heater! :)