Tetra 26446 HT Submersible Aquarium Heater With Digital Thermostat, 100-Watt, Multicolor, 10-30 Gallon

Holding temperature at 77°F
I installed this water heater for my 5 gallons fish tank. It’s constantly holding the temperature at 77°F. I went with this one because it is a Tetra product, It has to be something reliable. I’m not planning on cooking my fish. There is no noise level noticeable, I did not notice any leakage, so far has been very safe and working well as expected I install behind the black glass on my aquarium so you cannot actually see on this picture, but it’s working great.

Good heater
The heater works great and keeps the tank at a desired temperature. I do wish it had a on and off switch rather than having to use the plug.

Worked for 2 weeks!!!
Got this 2 weeks ago and was thrilled that it kept my 3 gallon tank warm and my betta happy… until it stopped working last night after I cleaned the tank and changed partial water. It stopped working all together and water is ICE COLD this morning! The light is green and will occasionally turn red for a few seconds before going back to green (which is supposed to indicate the the water is at the correct temperature). Still cold. I called Tetra customer service after reading many of the reviews here with the same issue. I explained what happened and asked if there is anything I could do to fix it or reset the heater as another reviewer mentioned that customer service gave instructions which fixed the issue. The customer service rep I spoke to would not help or even talk to me further if I could not tell him the temperature. I explained that I do not have a thermostat therefore I wouldn’t be able to check the temp but I assured him that the water was noticeably cold to touch in comparison to the warm water that has been consistent in the tank in the 2 weeks I’ve had this heater and tank. He rudely continued to cut me off and said that he couldn’t help me if I don’t have a temperature and he became more and more condescending in his tone has he continued. His customer service was TERRIBLE! I told him that I understood he needed to know the actual temp and that he couldn’t trust the temperature based on touch, so I asked if he could at least tell me what the possible options are as far as fixing this issue would be as I saw many other amazon reviewers shared the same issue. He became increasingly frustrated, increasingly rude, saying that he needs the temperature to know if he needs to send a replacement etc. I graciously explained that it was not my intention to get a replacement. I just wanted to know if he could help me troubleshoot so that I can attempt to fix my heater before my betta dies. I’m not interested in waiting for a replacement heater to come in the mail. Eventually I just asked to speak to his supervisor multiple times before he finally he basically said (like a child with a bad attitude) “Fine…..” and he patched me directly through to someone’s voicemail. I WILL NEVER PURCHASE TETRA PRODUCTS for the simple fact that customer service is NOT a priority to them. A simple “I’m sorry you’re having trouble with your new heater. Tell me what’s happening and let’s see what we can do….” would have been great and I would be willing to go to the nearest pet store and buy a replacement myself if he was willing to help me troubleshoot and exhaust all options first. Instead, the gentleman has no customer service training, does not know the meaning of showing empathy, and is not interested in helping anyone… unless you can tell him the temperature of the water even though this heater doesn’t have a thermostat in the first place.

Won’t shock your fish.
I like this heater, the one I replaced with it would send out electrical surges that would kill my fish. Heaters that come with the aquarium set up aren’t submursible so placing then below the water line isn’t good. I lost 20 fish with it. This one is made for putting it down in the water. The only thing about it is, you can’t adjust the Temperatur other than that it’s a great heater. I bought 3, 1 for my tank and 2 for my son’s.

This heater works fantastically.. I ordered it for my 3.7 gallon aquarium and it had no trouble heating the water up to 76° and maintaining that temperature even in winter when the indoor temperature in my house can drop to about 60° or lower.It has a long cord so you don’t need to have your aquarium by the power source which could be dangerous.It secures to your tank by a suction cup which is very strong.. if secured correctly the heater will not come off.Good heater at a good price.. it works great can’t complain.

This heater has worked great after my last one died suddenly. It doesn’t have the option to change the temperature, but for my needs, that is no issue. I do hope there is no chance for the regulation to fail, however, I have it plugged into a temperature controller anyway, so I will know if it goes too high or too low. So far no issues. Using it in a 10-gallon tank.