Review on Energy-efficient Betta Heater for Small (1.5 gal.) Tanks - Fully Submersible Aquarium Heater – Automatically Reaches Preset Temperature – Easy Installation with Suction Cups by Melissa Brewer

The description here is misleading and does not match the description of the packaging. According to here the heater starts heating at 74 and stops when the heater reaches 77, but the box says it starts at 77 and stops at 82 degrees. Quite different, which is why I gave 4 stars instead of 5 because of this misleading description. It works well in my 2.5 gallon aquarium. Can't confirm how long it will last as I've only had 3 cool days since I got it and usually my room temperature water gets hot enough now that it's summer. I need to check a thermometer and it seems to be heating up as stated on the box. Once the water drops below 77 degrees I have not had my tank brought to 82 degrees as it is a bit uncomfortable for the bettas. This is a temporary heater as I plan on converting my betta to a 5 gallon soon. If you buy this heater or any other heater, make sure you have a thermometer so you can check the water temperature yourself. You can never be 100% sure of the accuracy of a heater, so always check the temperature yourself with a separate thermometer rather than just relying on a built-in heater. The suction power is great, but it lasts. It's also a very small heater and doesn't take up too much space in my aquarium. I have enough space for my jewelry and my rooster doesn't seem to mind the heating.