HITOP Mini Submersible Aquarium Heater - 25W 50W 100W 200W 300W Small Heater for Fish Tank 1-75 Gallon with LED Display (25W)

Easy to set the device and understand. Fits well in a corner without obstructing the tank view. Great choice for a tank heater.

Update: I reduced the rating to 1 star because the seller reached out to me only to blame me for their products issue. They tried to say I had set it on Celsius. I did not. It had been running for a week at 77 just fine. I had not touched it when all of the sudden it was up in the 90s. I bought 2 of these heaters and I know how they work. Both were set on Fahrenheit. The digital display went crazy when the heater got too hot and the numbers were reflecting weird. Besides if what they were saying was accurate, that I accidentally set the heater to Celsius, that is also a defect in their product. It should not reset so easily that I wasn’t even aware of the change. I would have noticed the display change immediately too. Sorry, but this product is a fish boiler piece of garbage. If I could rate it lower than 1 star, I would.Initial review: bought 2 of these heaters and one worked great. The 2nd one, the temp controls went crazy. It showed 33 which is not supposed to be a setting. The actual temp in my aquarium was 92. Thankfully I didn’t have any fish in the tank yet. Would not recommend these especially in a small tank where the temp can easily swing. Tossed both and ordered new different brand heaters.

Temperature fluctuates about 4°

I ordered this heater because it seemed small enough to fit into the back section of my Fluval View aquarium. And fits just right. Easy to set the temperature. Has been constant at 76. I am keeping a close eye because of other reviews that mentioned overheating the water. So far no problems. It seems well made. I did not use the temperature tape that came with it.

Can barely keep my 5 gal aquarium at 82F in a 78F house