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AQUANEAT Aquarium Heater, 25W Small Betta Fish Tank Heater, Mini Preset Water Thermostat with a Thermometer

  • Based on 709 reviews
Condition: New
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Availability: In Stock.
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Arrives Sunday, May 3
Order within 7 hours and 6 minutes
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Size: 25W


Features

  • Mini Size: The heater is only 4.5 in length making it a great choice for small sized tanks from 3 to 5.5 gallons without taking up much space and obscuring the viewing area.
  • Easy to Use: The small 25W aquarium heater is preset to 78F which is a perfect temp for Betta and most of other tropical fishes, and no extra setup needed just plug and play.
  • Easy to Check: The indicator light turns red when it is heating and it turns green when it is resting so it is easier to do a quick check every day.
  • Includes: 1x 25W Small Aquarium Heater, 1x Suction Cup, 1x Free Thermometer Strip
  • Cautions: Always keep it fully submerged under water before plugged in, and unplug it and wait for at least 10 min before you do aquarium maintenance or take it out of water.

Package Dimensions ‏ : ‎ 5.35 x 2.64 x 2.4 inches; 4.66 ounces


Item model number ‏ : ‎ SDH-125


Date First Available ‏ : ‎ July 20, 2023


Manufacturer ‏ : ‎ AQUANEAT


Best Sellers Rank: #3,977 in Pet Supplies (See Top 100 in Pet Supplies) #9 in Aquarium Heaters


#9 in Aquarium Heaters:


Customer Reviews: 4.3 4.3 out of 5 stars 709 ratings


Item Weight: 4.6 ounces


Manufacturer: AQUANEAT


Item model number: SDH-125


Date First Available: July 20, 2023


Item Package Dimensions L x W x H: 5.35 x 2.64 x 2.4 inches


Brand Name: AQUANEAT


Target Audience Keyword: fish


Directions: Always keep it fully submerged under water before plugged in, and unplug it and wait for at least 10 mins before you do aquarium maintenance or take it out of water.


Warranty Description: we provide 30 days of warranty and lifelong technique support, feel free to contact us if you have any problem.


Model Name: Heater with Thermometer


Color: Black


Size: 25W


Included Components: A Sticker Thermometer


Specific Uses for Product: fish bowl, fish tank


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Sunday, May 3

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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Top Amazon Reviews


  • Not being used for aquarium, but to keep chicken water warm
Size: 25W
I use this water heater for my chickens water. It keeps the water warm and the chickens enjoy warm water.
Reviewed in the United States on November 19, 2025 by Boardergrl

  • Great size
Size: 25W
Perfect for my little shrimp tank. Durannle stickiness is okay. Works well so far while cycling
Reviewed in the United States on November 17, 2025 by Chelsea

  • Good so far!
Size: 50W
Very good prize. And the quality seems to be good so far from the 5 that I bought.
Reviewed in the United States on November 14, 2025 by Joseph Compton

  • Great value, good design
Size: 25W
Worked a little too well in my off sized tank (8 gallon). I was able to make it work with a timer. I like the minimalist design, and I’ve had this a while, so I can say it lasts without issues.
Reviewed in the United States on October 18, 2025 by L.R.

  • 👍🏼
Size: 25W
Love this heater works well great for small tanks
Reviewed in the United States on November 18, 2025 by Cheryl Echevarria

  • Does not work for long and could fry your fish
Size: 50W
The thermometer worked good until yesterday. I checked the tank temperature and it was 86 degrees and going up. I've only had this since August. Very disappointed in this product plus if I hadn't noticed the temperature it would have killed my fish and still could. I bought a different one same brand for another tank. It's working good but now I can't trust it. I would not suggest buying this one it doesn't work for long and could fry your fish. ... show more
Reviewed in the United States on October 20, 2025 by Donna Barr

  • Easy to use!
Size: 25W
Perfect for my African dwarf frog tank. Keeps the tank where it needs to be. Easy to instal too. Have no issues with it
Reviewed in the United States on November 5, 2025 by Julia Prebonick

  • Too Hot
Size: 25W
Arrived on time and in good condition. In a 2 1/2 gallon fish tank the water temperature reached 80 degrees, not 78 degrees. A little too warm for my needs; since then I purchased a 15 watt heater that has an external temperature control dial. For a little more money, I have a working aquarium heater. ... show more
Reviewed in the United States on November 5, 2025 by Amazon Customer

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