Review on FEDOUR Submersible Aquarium Heater with Protective Cover, Adjustable Thermostat for 5-40 Gallon Fish and Turtle Tanks - Available in 30W, 50W, 60W, and 120W Options by Mariah Ray

Okay, this heater is a pain to suck on. Keep in mind that suction power may be better if you install it during initial aquarium setup before adding water. Vacuuming when everything is in place will give you a headache. The description says it's 5-10 gallons, I have a 5 gallon tank and it doesn't fit vertically. It says the whole uuit needs to be submerged in water, you can't do that in a 5 gallon tank so I had to put it on the floor. It's one of the ways he says you can mount it, but it becomes a lot easier to read and set up when it's upright. Now for the temperature control. The ideal temperature for bettas is 78-80°. I set the temperature to 79° and thought it was perfect. NO! After about an hour I check, the temperature in the tank is 82°. While not bad, it's not the temperature I set. It's been a week and I'm still setting the heater temp. I set it to 76° and it rises to 79°, but at night it drops to 77°. I changed it to 76.5° and it seems to stay stable. And the temperature gauge sticker is useless. The thermometers in the tanks are inaccurate. The only thing I've found to get an accurate temperature is a meat thermometer, obviously one not used for meat. If you play around a bit, it does what it's supposed to. If we weren't in the middle of a pandemic where everything was closed and nothing to do, I probably wouldn't be wasting so much time messing with this thing.