Tetra HT10 Submersible Aquarium Heater & Electronic Thermostat, 50-watt

Tetra 50 watt heater. Absolutely does not work I have 50 watt in my 5 gallon tank absolutely and I have freezing water the red and green light absolutely do nothing the only time you see it is if you plug it in or unplug but if you blink you'll miss it have they commented as of why the light doesn't stay on to tell us it's heating? And you can touch that thing while it's in the water and it's cold as ice

Everytime I put my hand in the water it is freezing cold. My fish only stays on the bottom of the tank and is getting I’ll because this heater doesn’t function despite being on the green light. This is extremely frustrating and I don’t recommend people use this unreliable product. I have had to switch to putting hot water in every night to make sure he doesn’t freeze in June.

THIS ITEM DOES NOT WARM THE WATER...the red light only comes on for a few seconds and then turns off the GREEN LIGHT STAYS ON, but the water never gets warm!!! Green light is standby. It stands by forever!!!

I needed a heater for 10 gallon tank and this has been perfect match. Price is right and so easy to install. No fuss adjusting temp either. My goldfish and Zebra snails like the warmer water! Absolutely No problems to date, but I know I can reach out at any time to customer service.

Do not buy! It genuinely is a waste of money. The red light comes on for a minute to two then stays green and DOESN’T HEAT AT ALL.

Preset temp is easy. Works well in 5gal. tank. It is bigger than I expected, check the size description for size.

Do not trust the 1 star reviews. This heat works great for my Aquarium! It has never gotten to hot or to cold, never has burned my fish, and this heater has never stopped working, but i might have to turn it off in the summer because where I live, it gets 120 Degrees outside, and that could overheat my lungfish water.

I didn't realize that the heater is already set for around 76 degrees f, but my goldfish seem to like it because they keep swimming around it. every once in a while I do check my water to make sure it isn't too warm.

Keeps my fish and snails nice and warm... I have a 2.5 gallon and a 3 gallon fish tank and this is perfect for them.

This heater was purchased for 2 of our 5 gallon tanks. It works ok in one but does not work at all in the other tank. It seems to be a hit and miss with this heater.