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DaToo

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

  • Based on 4,750 reviews
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Availability: In Stock.
Fulfilled by Amazon
Arrives Monday, Apr 13
Order within 5 hours and 39 minutes
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Size: 25W


Features

  • 25W Betta Aquarium Heater: Creating and maintaining a perfect and comfortable water temperature for our cute fish is not easy, which requires a lot of effort. Now DaToo MINI 25W Aquarium Heater can help you make this easier. Precise and constant temperature, no need to set, keep the temperature of fish habitat in the best state at all times. You will find it very easy and happy to take care of pet fish!
  • Precise And Constant Temperature: No need to set, DaToo Fish Tank Heater will automatically keep the water temperature of the fish habitat at 78F. This temperature is very suitable for betta and most tropical fish. When the water temperature is lower than 78F, the heater starts to heat and the red light is on. When the temperature reaches 78F, the heater stops heating and the green light is on. DaToo will always maintain this comfortable temperature for your beloved fish!
  • The Smallest 25W Betta Heater: For most fish lovers who have small fish tanks of 1 to 5 gallons, a small heater means more space for fish. This is the smallest 25W aquarium heater on the market, only 0.2 inches. No matter how small your fish tank is, it can be used perfectly in it, and you can't even find it. Very MINI!!
  • Safe And Durable: Unlike traditional plastic seals, DaToo uses a rubber sealing layer, which ensures that DaToo has better sealing and safety performance, and will never leak electricity or water. Quartz glass material, explosion-proof and crack-proof, more sturdy and durable, without worrying about damage.
  • One Year Warranty & Satisfaction Guarantee: This heater is ideal for 1 to 6 gallon small glass or acrylic desktop aquariums. When in use, it needs to be submerged 100% in water. We provide one year warranty and 24 hours professional customer service. Buy With Confidence!

Description

The Smallest 25Watt Aquarium Heater For Your needs Specification: Power: 25Watt Voltage: 110V~120V/50~60Hz Heater Size: 4.90.90.9inch Power cord: 3.9ft Application: 1 to 5 gallon aquarium Features: - The Smallest 50W Heater On The Market - 78℉ Constant Temperature - Rubber Sealing Layer - Quartz Glass Material - One Year Warranty And 24 Hours Professional Customer Service Why Choose DaToo MINI 25W Aquarium Heater? 1. No Need To Set: DaToo MINI 25W Aquarium Heater will automatically keep the water temperature constant at 78℉. Simple and convenient, very suitable for beginners. 2. The smallest 25W aquarium heater: Only 0.2 inches in length, the smallest 25W heater on the market. No matter how small your fish tank is, it can easily meet your needs. 3. Safe: Unlike traditional plastic seals, DaToo uses a rubber sealing layer for better sealing and safety performance, and will never leak electricity or water. 4. Durable: Quartz glass material, explosion-proof and crack-proof, more sturdy and durable, without worrying about damage. 5. One Year Warranty And 24 Hours Professional Customer Service, Buy With Confidence! Select DaToo Products= Own A Private Aquarium Housekeeper. JUST DO IT, Let’t Go!!

Brand: DaToo


Special Feature: High Accuracy


Color: Black


Age Range (Description): Adult


Included Components: Free Thermometer Sticker


Outer Material: Plastic


Display Type: Digital


Product Care Instructions: Wipe Clean


Unit Count: 1.0 Count


Power Source: Corded Electric


Package Dimensions ‏ : ‎ 5.47 x 2.72 x 2.36 inches; 4.66 ounces


Item model number ‏ : ‎ DT-25A


Date First Available ‏ : ‎ July 17, 2020


Manufacturer ‏ : ‎ DaToo


Best Sellers Rank: #2,500 in Pet Supplies (See Top 100 in Pet Supplies) #3 in Aquarium Heaters


#3 in Aquarium Heaters:


Customer Reviews: 4.3 4.3 out of 5 stars (5,595)


Brand: DaToo


Special Feature: High Accuracy


Color: Black


Age Range (Description): Adult


Included Components: Free Thermometer Sticker


Outer Material: Plastic


Display Type: Digital


Product Care Instructions: Wipe Clean


Unit Count: 1.0 Count


Power Source: Corded Electric


Model Name: DT-25A


Item Length: 4.9 Inches


Upper Temperature Rating: 78 Degrees Fahrenheit


Reusability: Reusable


Immersion Depth: 0.9 Inches


Lower Temperature Rating: 78 Degrees Fahrenheit


Style: Basic


Indoor/Outdoor Usage: Indoor


EU Spare Part Availability Duration: 1 Years


UPC: 745408757995


Manufacturer: DaToo


Item Weight: 4.6 ounces


Item model number: DT-25A


Date First Available: July 17, 2020


Item Package Dimensions L x W x H: 5.47 x 2.72 x 2.36 inches


Brand Name: DaToo


Target Audience Keyword: fish


Size: 25W


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Monday, Apr 13

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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Similar Products

Top Amazon Reviews

    • Heats small tank, stays in place, temperature not adjustable
Size: 25W
Review Image by whitefreeze whitefreeze
Have had it plugged in and running for a few days in my 1.5-gallon tank, and it is working great! The red light turns on when heating; green light when it's at temperature (~78° F), which I've been monitoring via a digital thermometer (temperature seems to stay right between 77.5° and 78.5°). I'm not able to adjust the temperature, but 78° is right around the temperature I'll be needing, anyhow. This heater keeps the temperature in the target range, whereas the 10W heater that came with the tank couldn't, as the water was always way too cold previously. The included thermal tape thermometer kind of works, but is not very accurate and it's really hard to discern the colors; it's nice to have, but I'd recommend something else if you need more temperature accuracy than ±5° and you have a larger tank or a colder room. Also, the suction cup fits the heater well and is nice and soft, holding to the plastic tank really well! (I was a little impressed with that, actually.) ... show more
Reviewed in the United States on February 1, 2026 by whitefreeze whitefreeze
    • Good for 5 gallon tank
Size: 25W
Works well for my 5 gallon tank. Keeps my fish warm in the winter and snails seem to like to hang out around it. I have the thermometer on the other side and it keeps it at perfect temperature so I know it’s working through throughout the tank.
Reviewed in the United States on February 12, 2026 by April Chavez
    • Great so far
Size: 25W
Review Image by My2Cents My2Cents
Great heater. Bought it in a hurry without much research and I'm really happy with it. I have it in a 5 gallon tank and it keeps it at around 74-78 for the most part. It fits in the back of my tank well so it is concealed, keeps it at an even regular temp even with our house temps fluctuating, and I've had no issues with it. Easy to use just plug and go. ... show more
Reviewed in the United States on February 2, 2026 by My2Cents My2Cents
    • They work
Size: 25W
I have ordered a ton of these. So far, most of them seem to work pretty well. They keep the tanks around 78F, give or take a tiny bit. You can’t adjust the temperature since it’s preset. I’d like it if they came in a smaller size and also if they had a shatter proof option. These are glass without an outer casing so they might shatter if they overheat. These are not mini but they’re not huge. They’ll work for a 5 gallon tank or bigger. Don’t use these in anything under 5 gallons. They’re too big for that and might overheat. The heaters are easy to use. Just attach the suction cup, place in tank under water, and plug them in. ... show more
Reviewed in the United States on February 13, 2026 by bee
    • Cute, small, easy to tell that it's working perfectly
Size: 25W
I'm using this for a 3-gallon shrimp tank. It's tiny. It's cute. There is a very belt-and-suspenders approach to being sure this thing is working properly. It lights a little even when it's not heating the water (I expect it's not heating the water when the room is nearly 90 degrees in August). The light is really only visible when the tank is dark and there isn't too much light in the room, but it's a small square by the bottom, just to clearly indicate it is working. I like that assurance. The little thermometer, which is also tiny and out of the way, would be another indicator, again if it weren't August and showing the water temperature in the 80s without the heater. So you can be certain, if there is a problem, you will know. But the ambient room temperature does lead to another point. It's small and I don't think it's that powerful. For me, the room is never going below 70 degrees. I'm in an apartment building with a lot of elderly residents, and the super needs to keep the place warm bordering on hot for them. I need the heater. The water will get too cold for the shrimp without it. But not more than say 10 degrees below their comfort level. If you're thinking a tank in say a garage (I know some people who use that as an office and keep a betta there) and you're prone to reasonably cold winters, then this might not be the thermometer for you. The shrimp seem to think it's a nice platform to sit on. I usually find at least one perched on top. I like especially how deep I can store it and the suction cups keep it firmly in place. If I'm only doing a one gallon water change (they're shrimp -- they have a really low bioload so changing a gallon a week is fine) then I can keep it plugged in while doing the water change and it stays fully submerged the entire time. ... show more
Reviewed in the United States on August 6, 2024 by Ivy Reisner
    • This little heater is a gem, works great, priced great.
Size: 25W
My Betta tank is in my poorly designed bedroom, heating vent at the top of the wall around the corner from the main part of the room so it is always cold in here. I was having a hard time keeping the water temperature at a good level so I ordered this little heater. Within 15 minutes of installing it, the water temperature rose to 78 degrees and is staying there. Very easy to read, when it lights red it is warming the water, when it lights green the water is at the pre-set temperature of 78 degrees so you don't have to worry about adjusting it or turning off/on. Very affordable, small so it fits into a small tank, good quality materials, comes with a temperature strip. Definitely recommend! ... show more
Reviewed in the United States on December 1, 2025 by Lynda Palimas
    • Nice little heater
Size: 25W
Keeps our betta's 5 gallon tank at 78-80.7 degrees depending on our room temperature. Even after a 30-40% water change it doesn't struggle to bring the water temp back to perfect. It was plug and play out of the box. The thermometer strip that came with it never worked to tell the temperature but I was using a separate digital thermometer anyways. Awesome price too!! ... show more
Reviewed in the United States on November 28, 2025 by YuiPie

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