Mini Aquarium Heater 25W Small Fish Tank Heater 25 Watt with Free Thermometer Sticker

I recently purchased the DaToo Mini Aquarium Heater 25W for my 3-gallon betta tank, and I couldn’t be happier with it! It’s small, compact, and fits perfectly without taking up too much space in the tank.The heater is preset to 78°F, which is the ideal temperature for bettas, and it keeps the water at a steady, consistent temperature without any fluctuations. I also love that it comes with a free thermometer sticker, making it super easy to monitor the temperature at a glance.Setup was quick and simple, and it started working right away. My betta seems much happier and more active since I started using this heater. If you have a small aquarium, this is the perfect heater—reliable, affordable, and efficient. Highly recommend!

The PERFECT fish heater for a simple tropical small tank. No fush involved, no managing the temperature reading. Quite a value and works exactly as you need it to with a simple design for a consistent temp for your fish babies!

I have been keeping freshwater aquariums on and off for almost 30 yrs. Heaters have always been the same tech they are now. The BIG takeaway is to keep them cool and constantly sampling flowing water. I have ALWAYS set mine up by the pump outflow and kept them completely submerged. DO NOT keep them plugged in while changing water. This lowers overheating and temperature component shock which leads to a lot of the issues seen in the reviews here. If you have a betta in a setup with no water flow... do not get a heater until you have an actual tank setup. STOP putting these in bowls and expecting them not to blow up.Temperature accuracy and what I have learned with this unit... I keep mine in the pseudo sump unit in the 5 gallon kit I bought. This way water is constantly flowing around the unit. I have an air stone in this same compartment and when it is running it cools the unit more which lead to it running between 80 F - 78 F. When the bubbler is off it cycles and stays a consistent 78 F. So, over agitation can lead to the unit sampling too cool and cycling more. So, I have put my bubbler on a timer and do spaced out 30 min cycles throughout the day. This has resolved the issue with this unit. It needs gentle water flow for accurate sampling and heating. Over agitation can lead to it falsely reading the water as cooler leading to the varied warmer temps.

I have a large glass bowl that I use as an aquarium for my small tropical fish and I got this heater to use in it because it is only 2-3 gallons in size and this heater is perfect for it. It works great! I have purchased small heaters before and had trouble with them i.e. not really able to control the temperature well, but this one seems to be working great and keeping the temperature right at the correct level for my tropical fish without overheating the small tank. So I am happy with it. It came with a free stick on thermometer which didn't actually work i.e. the temperature would not show on it so I pulled it off the side of the tank to throw it away and it left sticky residue on the outside of the tank which was difficult to remove. I think it was included so you could verify that it was keeping the temperature at the right level. So the small stick on temperature strip was a failure but using a regular thermometer in the tank shows that it is keeping the temperature at the correct level and the heater itself has a little indicator light which shows when the temperature is safe (green) and when it is too hot or cold (red) and that works. So I threw the temperature strip away because it did not work and with some difficulty I finally got it off the side of the tank. It left little sticky bits behind on the glass that I had to scrape off. But the little heater works great and has its own internal safety indicator light where red equals out of safe range and green means it is safe and that does work. But the external strip thermometer didn't work and when I tried to remove it from the outside of the tank it was difficult to get the sticky adhesive off the side of the tank as some of it pulled off the little strip and stuck to the exterior of the tank glass and was difficult to remove from the glass. So I threw the small thermometer strip away as it was useless i.e. no temperature showed on the strip after a full day but the heater itself is great.

Exactly as described and simple to install. Works great and ideal for small tanks. Used it for a 1.5 gallon tank and it kept right on temperature.

Perfect for 5 gallon or under aquariums. It's preset temp is great for community or tropical fish, shrimp, etc. Small size, fits well in smaller tanks. I really like that comes with a sticker to help keep track of temps. It's plug and play, easy to use. Has green and red lights indicating if is turning on to heat water or at set temp, so easy to read that way. Good quality, this is my 3rd one for one of my many betta tanks. I would recommend these!!

The heater for the a small tank works amazingly!But if you’re buying this for the temperature gauge don’t because it doesn’t even work

Works great the temp gage is hard to tell where it’s at. But heats the water well.