AquaMiracle Upgraded 50W Small Aquarium Heater Fish Tank Heater Turtle Heater Super Mini Aquarium Heater, Dry-Run/Overheating Protection and Memory Function, Dual LED Display, for 5-10 Gal Tanks

So far it works great!

I wish they had a separate probe for temperature, but I don't know that it makes any difference, I've just always used that style. I am using these in both 5 gallon buckets and 5.5 gallon glass aquariums, and they are really easy to set the temperature, have a bright and easily read display, good suction cups (surprised to see these small units come with 2 cups.) as a general rule I do not use glass heaters, but because these are temporary while I set up a sump, I didn't want to spend the money on titanium, and I don't even know if titanium heaters can be purchased at this low of a wattage. The glass seems plenty thick and the large rubber bumpers on the top and bottom stick out enough that they should be pretty durable. I think for the money these are great heaters, and even after I am done with them I'll be happy to have them around as backup. I've been running them for a few weeks so I can't speak to longevity, but they are doing their job, and as long as you do your part placing them properly in an area with good flow, they are very stable. Unlike another small cheap heater I have that came with a tank, these stay in place, so I feel safer about them not falling against some hardscape or getting buried in substrate.

using it on a 3 gallon tank and it regulates the water temp as it should, digital display of current temp and set temp is a nice feature

I have the 100W version in a 10 gallon tank and it works great, even in the winter when I let the room temperature drop to below 50 F. The heating unit is small and easy to place in the tank. It also came with two strong suction cups for mounting it against the glass. The control unit is very easy to use, shows the current water temperature and set temperature, and can also be switched between Centigrade and F. It is definitely better than the older style heaters. Highly recommended!

The water is 2 degrees hotter than what you set it for. No biggie. I turned it off in the summer. My fish can tolerate up to 68. I only use it in the winter and it works well. Highly recommended.

I use one of these in each of my 3 gal and 15 gal.While I love that I can turn up the temp easily with the external button, the temp gauge is not accurate. It will tell me the heater itself is to temperature, or even above the correct temp, and then stop heating the water. Meanwhile the water will stay 5+ degrees cooler and I’ll have to monitor it with an outside thermometer.I love the size and ease of temp change but hate how inaccurate it is.

I bought a different model with the same form factor 2 years ago and loved it. But it died last week. I bought the AquaMiracle for its form factor but it was a fraction of the cost of the original. It actually works fine, but I have two observations: 1) The power cable is much shorter than ideal. Because of a peculiarity of my setup, I can get by without using an extension cable but many users will require one. 2) The temperature indication is 2 degrees F. high. I.e., if I want the tank to be at 80 degrees F., I need to set the control at 78 degrees. I'm using several "stick-on" contact thermometers that I've used for years, and the previous unit was always right on the money, so I know that I can trust them. Two small matters, but they account for the 4-star rating. I would STILL buy it again.

Works as intended.