FREESEA Aquarium Fish Tank Heater: 100W Small Submersible Turtle Heater with Adjustable Temperature External Controller for Betta | Saltwater | Freshwater | 10-20 Gallon
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This item is eligible for return within 30 days of receipt
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Availability:
In Stock.
Arrives
Wednesday, Sep 10
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Size: 100Watt
Features
- FREESEA Aquarium Heater: 100W betta fish heater, voltage: 110~120V, is suitable for use in 10-20 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
Is Discontinued By Manufacturer : No
Product Dimensions : 2.5 x 1.5 x 3.5 inches; 8.08 ounces
Item model number : FS28-100W
Date First Available : August 8, 2018
Manufacturer : FREESEA
Best Sellers Rank: #19,714 in Pet Supplies (See Top 100 in Pet Supplies) #32 in Aquarium Heaters
#32 in Aquarium Heaters:
Customer Reviews: 4.1 4.1 out of 5 stars 8,746 ratings
Item Weight: 8.1 ounces
Manufacturer: FREESEA
Item model number: FS28-100W
Date First Available: August 8, 2018
Item Package Dimensions L x W x H: 5.63 x 3.7 x 2.64 inches
Item Dimensions LxWxH: 2.5 x 1.5 x 3.5 inches
Brand Name: FREESEA
Target Audience Keyword: fish
Color: Submersible Heater with External Controller
Size: 100Watt
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Wednesday, Sep 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.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
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Similar Products
Top Amazon Reviews
Size: 50Watt
This is a good product. I had one of these at a higher wattage in my 20 gallon tank for several years and it only recently stopped working.
Reviewed in the United States on July 17, 2025 by Karen Scalio
Size: 50Watt
I was a little nervous about this given some of the reviews, but pretty much every aquatic heater on Amazon has a decent amount of 1 star reviews. I'm using this in a 3 gallon tank I use for raising guppy fry until they are large enough to move to the larger aquariums I have for them. This has been amazing! I haven't modified it at all and used it for about a month now and I'm happy to report that every guppy survived. This heater does sometimes vary by 1 degree when the temperature drops below what it is set at but it quickly heats up again to the set temperature and it is never more than 1 degree lower which was not an issue for the babies. Honestly I prefer this to it always keeping the temp higher than what I set it at like some other models do since it pretty much guarantees that it will not cook your fish. None of my fish attempted to go behind the heater, so if I had a Betta I might place some netting around the suction cups on the back as one other reviewer did since Bettas do enjoy resting and hiding. Alternatively, I'd suggest giving your Betta more preferable resting places and hiding spots/keep the tank warm enough so he won't want to go behind the heater.
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Reviewed in the United States on March 29, 2022 by Kindle Customer
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.
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Reviewed in the United States on February 17, 2019 by Ms.Smarte Blonde
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
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
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Reviewed in the United States on May 15, 2025 by Eddy Fermin Diaz
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.
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Reviewed in the United States on December 29, 2024 by ElizaMe