Review on 🐠 Adjustable Aquarium Heaters - Hitop 50W/100W/300W, Submersible Glass Water Heaters for 5 – 70 Gallon Fish Tanks by Nicole Walker

I would say this thermometer did the job. Seems well done. However, it heats up a bit where you want it. I had 78 and the thermometer read 80. I turned it off to correct the difference and everything has been fine ever since. I would recommend this heater but don't install and forget. Come by from time to time for the first few days to check the temperature. That's a bit more for a 5 gallon tank. I had to turn it sideways and place it on the bottom of the tank to get it to fit, but overall it's worth it.