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FREESEA Aquarium Fish Tank Heater: 50W Small Submersible Turtle Heater with Adjustable Temperature External Controller for Betta | Saltwater | Freshwater | 1-10 Gallon

  • Based on 8,733 reviews
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Availability: In Stock.
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Arrives Tuesday, Mar 10
Order within 20 hours and 38 minutes
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Size: 50Watt


Features

  • FREESEA Aquarium Heater: 50w betta fish heater, voltage: 110~120V, is suitable for use in 1-10 gal betta fish turtle tanks and aquariums. The power cord is 5ft, long enough for indoor use
  • Double Safety Protection: When the top part of the turtle tank heater is out of water it will auto shut off. When the actual water temperature is higher than 94F, it will auto activate the overheating protection and stop heating
  • External Controller: The betta fish heater is adjusted by an external controller, which you can mount on the outside edge of the tank. Its convenient to adjust temperature that range from 63F to 94F
  • LED Temperature Display: Digital led temperature display shows the real-time temperature and error code on the screen. When the mini aquarium heater is heating, there indicator light above the digit is on red
  • 12-month Warranty: We are committed to providing high quality products and better service with a 12-month warranty. If you have any questions about the turtle heater you receive, please feel free to contact us

Material: Glass


Voltage: 110 Volts


Item Length: 3.5 Inches


Brand: FREESEA


Color: Submersible Heater with External Controller


Is Discontinued By Manufacturer ‏ : ‎ No


Product Dimensions ‏ : ‎ 2.5 x 1.5 x 3.5 inches; 8.15 ounces


Item model number ‏ : ‎ FS28-50W


Date First Available ‏ : ‎ September 17, 2017


Manufacturer ‏ : ‎ Guang Zhou City Freesea Industrial Co.,Ltd


Best Sellers Rank: #18,671 in Pet Supplies (See Top 100 in Pet Supplies) #25 in Aquarium Heaters


#25 in Aquarium Heaters:


Customer Reviews: 4.1 4.1 out of 5 stars 8,733 ratings


Material: Glass


Voltage: 110 Volts


Item Length: 3.5 Inches


Brand: FREESEA


Color: Submersible Heater with External Controller


Wattage: 50 watts


UPC: 722970219243


Manufacturer: Guang Zhou City Freesea Industrial Co.,Ltd


Item Weight: 8.1 ounces


Item model number: FS28-50W


Date First Available: September 17, 2017


Item Package Dimensions L x W x H: 5.55 x 3.7 x 2.8 inches


Item Dimensions LxWxH: 2.5 x 1.5 x 3.5 inches


Brand Name: FREESEA


Target Audience Keyword: fish, fish tortoise


Size: 50Watt


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Tuesday, Mar 10

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


  • Can be opened (without breaking it) in case of emergency
Size: 50Watt
I love these heaters I have them in all of my tanks. Today one of my kuhli loaches swam in there and couldn’t get out and fret not they can be popped open by the little clips on the bottom if someone decides to make it their home!
Reviewed in the United States on June 5, 2025 by Nathanael Sass

  • Great
Size: 50Watt
I recently purchased the FREESEA Aquarium Fish Tank Heater, and it has been a fantastic addition to my aquarium setup! This 50W submersible heater is specifically designed for small tanks, and it’s perfect for maintaining the right temperature for my betta fish and other aquatic friends. One of the standout features of this heater is its adjustable temperature external controller. Setting the desired temperature is a breeze, and the clear display allows me to monitor it at a glance. I’ve noticed that my fish are much more active and healthy since I started using this heater, which I attribute to the consistent temperature it maintains. The design of the heater is compact and sleek, making it easy to fit into my 1-10 gallon tank without taking up too much space. It’s also submersible, which means I can place it exactly where it’s needed for optimal heating. The installation process was straightforward, and I appreciated the included suction cups that keep the heater securely in place. I was also impressed by how quickly the heater warms up the water. It doesn’t take long to reach the desired temperature, and I feel confident that my fish are comfortable and safe. The heater has built-in safety features, such as over-temperature protection, which provides additional peace of mind. What I love most is its versatility; this heater is suitable for both freshwater and saltwater tanks, making it a great option if I decide to diversify my aquarium in the future. The quality of the materials used feels solid, and I expect it to last a long time. Overall, the FREESEA Aquarium Fish Tank Heater is an excellent choice for anyone with a small aquarium. It offers reliable heating, easy temperature control, and peace of mind for fish owners. I highly recommend this heater for keeping your aquatic pets happy and healthy! ... show more
Reviewed in the United States on November 5, 2024 by C

  • Update: Be aware! Heat increase alows bacteria and fungi grow!!!
Size: 50Watt
Update: March 1st, after two weeks of using heat, my Bandit start developing darkish spot on few scales near tail fin. First I didnt worry, but then literally in a week, spot got bigger, it started bulging and developed white color stuff on top of black looking scales. I realized heat allowed either fungi or bacteria grow rapidly. His tank is about 3gal, he is alone, no other fish. Got Beta antifungal drops and aquarium salt. Took out all gravel. I use distilled water with Betta complete water conditioner. Now I am using API salt and Pimafix fungal infection drops. For about last 3 days Bandit is lethargic and most of the time stays low or hides in his house. He was happy for first two weeks with heater hanging around it all the time. I never had any fish or Betas before, I got him in August 2017, he was healthy and spunky til recently. Now he doesnt seem to be hungry, I watch him for about 15 min to swim up to eat. Right now he sleeps in his house and wont come out. I am heart broken to think that I might have make him sick by heating up water. I change water every couple weeks. Bandit has fresh 3 live Marimo balls, which suppose to absorb impurities. I have water pump for circulation, heater right now is on 72, just about low comfort level. I been using Antifungal drops since Mar 5th, dont see any improvement yet, but it doesnt seem getting worse either. I absolutely hate to think I might have caused him getting sick! I spent so much money on this little guy for his comfort, but I didnt think I could cause him harm =(''' Apparently I need to learn how to care properly for Bettas, since I never before had any fish. I got him in Petco in August 2017. When I walked by Bettas, they are in those tiney round containers laying there docile, he was the only one who went bezerk and started pounding on container, which made me look at him. He was looking at me and I heard this voice in my head " get me out of here!" I even looked around thinking where did this voice came from? Next thing I know I reach for his container...That day I dropped over 100bucks. 3gal tank, gravel, food, water drops etc. I came home thinking how did that happen and how do I best care for him? I went to Petco to buy litter for my Izabella and ended up with Bandit. I love him, he was happy in his new home, being able swim around. Now he is just lethargic, hiding in the house. I am sure heat has something to do with it. Now I am trying to reverse damage. For people like me, who dont know much about Betas, this is lesson to be learned. Original review: I got this heater Feb 14th, plugged in and it heated up quite fast, I would say in 30min temp was warming to his comfort level. I set it for 78F. I have one Beta boy, on these cold arctic days water temp got below his comfort zone, as per thermometer. My Bandit was laying low and wouldn't swim around much. When I plugged in heater, he was drawn to it immediately, he was staring at it for a while and then just hanging around it for warmth. My poor Beta was cold without heater =(''' Now that water temp is comfortable for him, which is 22-26C or 72-80F, I can see his spunky self swimming around happy! His water thank holds almost 4gal, I have gravel, water pump, not filter, and heater, and I can see my Bandit is happy. Now he has better appetite also, and I don't have to watch him for 15min before he swims up to eat, now he eats right away. I realized that he wasn't comfortable in colder temps and I am very glad I got this heater for him! Very well worth the money thus far. I wish there was option for C temps, but its only for F. Instructions are very simple, immerse heater all the way into water, plug in and press temp button. I am glad for this purchase and my Bandit is happy! I recommend this heater. 4 stars only because no C option, otherwise 5 stars. ... show more
Reviewed in the United States on February 17, 2019 by Ms.Smarte Blonde

  • Would def buy again
Size: 100Watt
Great product, it keeps the aquarium nice and cozy. The only issue is the suction cups aren’t great.
Reviewed in the United States on April 18, 2025 by Amber

  • It killed my entire fish tank fishes - over heated the water on its own
Size: 100Watt
The media could not be loaded. Everyone please don’t buy this product if u don’t want all your fish to die like mines … I’ve had a fish tank for years with my beautiful variety of fish I’m so upset after so much work and money I’ve spent to maintain my tank safe for the safety of the environment for them and now this damm product killed them all I switched my old water heated and replaced it to this one a week ago and today April 14 2025 this product turned the water to the maximum heat possible causing all living fish to died , some fish were literally cooked and the water was smoking hot . Monsters ... show more
Reviewed in the United States on May 15, 2025 by Eddy Fermin Diaz

  • Beta approved!
Size: 100Watt
I love the ability to be able to see what the temp is! Super easy to use. Little light shows up when it’s heating. Easy setup up. Doesn’t get to hot either. My beta loves to prop himself up on it!
Reviewed in the United States on March 21, 2025 by Amber Ireland

  • Not good enough to keep
Size: 75Watt_
This was larger than I expected, which is my fault. They give an accurate measurement, I get other ideas in my head. Then, I hadn't thought about how obtrusive the lighted digital temperature would be in the tank. It can't be dimmed or turned off. Finally, the temperature is off. It consistently reads 4° higher than the actual temperature according to two other thermometers. I guess this isn't terrible. Consistently 4° off still let's you keep a consistent temperature. It was just too many little things for me. I will be returning it. ... show more
Reviewed in the United States on April 16, 2025 by Collins Family

  • good help
Size: 75Watt_
we used this heather before , ; and it works pretty well; we have it in outside water tank for turtles mostly in winter time. and sometimes we found them on top of it . this means that it keeps them warm enough . When is too cold we put them inside the house and in the summer no need . we just have to chenge them after rwo or three years depending of the used. we keep it on, all day during the cold. the tank is 25 gallons. ... show more
Reviewed in the United States on December 29, 2024 by ElizaMe

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