FREESEA Aquarium Heater with LED Display 100 Watt for 5 to 20 Gallon

So the heater did not overheat, but it fluctuated too much. I put it in my tank, and one second it was warm and the next it became extremely cold. It wasn't keeping a constant warm temperature. Returned it.

This thing is just way too big for what it is. The LED display is so ridiculously bright and unfortunately the heater overall doesn't work well for small tanks. It heats up the water way too much and doesn't properly regulate the temperature that I set it at. I ended up purchasing another small heater that works much better, plus without the obnoxiously bright temperature LEDs. Here's the one I got that I prefer much more and keeps the water right around 79 - 81 degrees for my betta fish: Aquatop Nano Aquarium Heater, 15-Watt (2.6 To 4 Gallon Aquariums / 77 Degree Fahrenheit Preset Temperature)I also bought a small temperature sensor with a suction cup that has the display outside of the water connected by a wire. Really the best setup for a small space that most betta owners will provide for their fish.

I got this one because of the form factor. I didn't want the cigar shape of most heaters. This one seems to work fine, and it's overall short height means it doesn't get exposed if I forget to unplug it while doing a water change, so there's that...The red LED setpoint display is supposed to be a "cool" feature, but it really just annoys me because it's always on, and you can't look at the aquarium without noticing it. That display should have been incorporated in the in-line setpoint adjust module, not in the in-tank part of the heater. Also, if you're going to bother getting that fancy, why not provide a C/F display option?

I love this heater. I have it so that I can just see the led temperature indicator through the plants. You can keep tabs on the temp from across the room but it isn't obtrusive. I love the controls on the cord so you don't have to pull the heater out of the water to change the temperature, and this unit is short enough to hide easily and not have to worry when you do a water change that it will expose the heater. Will see if it lasts. Edit: So far I have three of them in use and they are working perfectly. I bought a few more.

Perfect heater for my 2.5 gallon tank. It only displays in CELSIUS so pay attention when setting. There are some nice features: Blinking numbers when YOU are adjusting the temperature. Static number display indicates current tank temps. Red light under the static number display when set point has been reached. Also the temperature control button is flat making it hard to accidentally adjustment the temperature (by a playful cat or curious kiddos).

I only had this heater for 2 days so longevity is unknown but everything else is great so far! I need to keep 1 gallon jar for brine shrimp at 27-28C (~82F). This heater has compact rounded shape so it fits great in the jar, the controls are outside so I can make adjustments without making a mess, large numbers show current temperature in the tank, and even so the heater is 50W which normally would be too much for 1G tank, it maintains 27-28C temperature at all times. Most mini heaters don't even have a thermostat!

Great heater: clear and accurate read-out, and easy to install. I’ve kept a standard thermometer on the tank to check the heater’s accuracy, and it doesn’t disappoint. The fish seem a lot happier and more active in water that is consistently the correct temperature- a definite upgrade from our previous puck heater.

I have had many fish tanks over the years. I bought this for a beta bowl that sits near air conditioner vent and wanted to ensure even temperature. Temperature is easy to adjust from the outside and is very accurate with large bright numbers. comes in celsius only, but my stick-on thermometer has both F and C. so easy. BUT as it says in the product description, just make sure you turn heater off if you are doing a water change and the heater goes above the water line. The outside casing will melt. How do I know... well it happened to me, but i caught it in time and just a little bit of the casing melted. In any case, I was able to save it from the trash and it's been working just fine. If i did ruin it, i would have bought another one without hesitation. They do warn about this and it is common sense, just forgot to turn it off when i was doing a partial water change.

good

I bought this heater for a one-gallon tank! I have a betta fish and a zebra snail and they love it! At first, I was worried it was gonna boil my fish, but it didn't and what I...

I have 2 tanks with Betta fish in each and I have one of these heaters in each. One is 10 gallon and the other is 2.5 gallon.

The design is flawed and although it seemed to work well, the back is open to the coil by design and my Betta fish got inside and wrapped around the coil which cooked him.

You can adjust the heat up or down from a switch on the cord! No wet hands! It’s in Celsius but so is my thermometer and my book on bettas, so it works for me.

It's a little pricey, but it works and allows me to set a nice comfy temperature for my daughters betta fish.

I hated how short the cord is

stop working after few months, EE on display.

Works great and easy to use!

This keeps the water at a good temperature, but I think that it's too big for my 3 gallon tank it takes up a lot of space.