hygger Mini Glass Aquarium Heater Adjustable LED Digital Temperature Display Small Tank Heater for 1-6 Gallon Turtle Betta Fish Bowl with Protective Guard 50W

I’ve been using this little heater for about a month now in my 5 gallon cube tank & so far it’s working great! I specifically picked this heater because it doesn’t have any little holes on the sides like some of the other brands do - I have very tiny Sexy Shrimp & Bumble Bee Shrimp in there so I was very concerned about them possibly getting caught in the holes. The temperature is super easy to set & seems to be accurate when I compare it using my digital thermometer pen & also the little digital thermometer that I keep attached to the side of my tank. When I first started using it, I found that it was getting a little warmer than the temp I was setting it to so I set it slightly lower. The second day using it, I was able to set it to the temperature I wanted & it has been accurate & working perfectly ever since. I’m thinking maybe the heater just needed a little time to calibrate itself or something. The only thing I noticed it that it makes a very slight humming noise while on to heat up when it drops below the set temperature. It’s barely audible unless your standing right next to your tank in a completely silent room but I just figured I’d mention it. I highly recommend this little heater & will definitely buying more of them in the future.UPDATE 08/07/20I am now using it in my 5 gallon Fluval Spec which even though it’s the same amount of water, this tank is much longer than the 5 gallon cube I was using it in so I needed a little more flow for the heat to spread evenly. It’s still working but seems to consistently be off by about 2-3 degrees now no matter where I place it & even though I‘ve made sure to keep it clean & free of any algae/debris. I was also hoping that occasionally unplugging it to clean it would maybe reset/recalibrate it but it’s still slightly off. Basically if I want my water temperature at 78F, I have to set it for 80F. I always also keep a digital thermometer attached to the glass on all my tanks just as an extra precaution. I own several other Hygger products which have all been great but heaters in general just make me extremely nervous with so many horror stories in reviews!

Okay, the listing said "ideal for small fish bowls and aquariums 6.5 to 13 gallons." I thought I'd have to buy several of these things. It's keeping my 75 gallon tank at 80 degrees all by itself. And it heated surprisingly fast.I hope Hygger keeps making these things. I think my Nicrew died from calcium erosion; it had a remote that this doesn't have, so if you want to lower the temperature, you have to click through until it reaches the correct number and the lowest setting is in the 60s so that can take a little bit of clicking.That said, I love the digital display like an addiction. It's large, I can see it sitting on my couch. It's set for 80, when it dips to 79 the light goes on and it heats again. The slats are really narrow so small fish like dare devil Danios aren't going to lodge themselves in it. The suction cups are remarkably strong so it takes a little finagling, sliding around and slipping your finger nail in to pull it off.I think my only critiques are that it would be nice to have an up and down button to change temp, or a remote with up and down is cool. And make the cord a foot or two longer. It just about makes the power strip directly below with several loose inches for arranging cords. You'd probably have to use a different brand for longer tanks where there's one on either side.But so far, I've spent the last twelves hours whining with glee that I don't have to replace several gallons of cold water with hot every morning, my fish aren't freezing, they're happy and active. All automated. I can just enjoy watching them again.

I was so scared to order a submersible heater. I just kept reading horror stories about fish being cooked to death, or near death incidences, or fire hazards with these things. I knew I had to get one for my little guy though. I would go off to my cozy bed at night and just feel awful knowing I was leaving him in his cold tank. His fins were looking like crap and he wasn't super active being in that environment.I have the Hygger mini air pump and was pretty happy with it so I decided to try this brand with the heater and the reviews looked pretty good. I have had it for a couple of weeks now in a 2.5 gallon tank. I have it set at 77 degrees. It will drop one degree at times and then the light will come on (on the unit in the tank where the current water temp is ALWAYS displayed) and the heater will kick on and heat it back to 77. It operates like your home thermostat on your furnace. I have a suction cupped thermometer in the tank too and it consistently reads the same as the heater thermometer. The suction cups on the heater are very secure. It hasn't moved or gotten loose since I put it in the tank. It's quiet. I hear nothing coming from this heater. I see nothing leaching off the materials into the water. The vents on the front do not appear to pose any threat of pulling him in by his fins.Betta seems very happy. He swims around all day long and will sometimes hang out by the heater. His fins looks better too. Obviously, he is much less stressed being warm. I would recommend this item. When he moves to his upgraded home I will get another of these for that sized tank.