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PULACO 25Watt Mini Aquarium Submersible Betta Heater with Free Thermometer Strip for 1-6 Gallon Fish Tanks (Preset Temperature 78℉)

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Availability: In Stock.
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Arrives Monday, Apr 13
Order within 6 hours and 43 minutes
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Size: 25W up 1 to 6 Gallons


Features

  • Betta Heater: This Fish Tank Heater should be 100% submerged into water, Ideal for small glass or acrylic desktop aquariums up 1 to 6 Gallons, not suitable for less than 1 gallon tank.
  • Quick and Easy Installation: Vertical or horizontal placement using, Aquarium heater automatic temperature control 78F, no need to adjust temperature, easy to operate, fishes happy.
  • How it Works: Plug in, red light turns on, the heater will start working until water temperature up to 78F, and red light off, then the green light will turn on, heater stop working and keeping constant temperature 78F. Accuracy:3F
  • Note: Do not operate or leave product plugged in when your water tank is out of water, heater should be fully submerged into water. Please install a water pump or filter to help water circulating while heating.
  • SATISFACTION GUARANTEED: Our Aquarium Heater is built with durability in mind and safety for every design. In the remote possibility that youre not satisfied with our product, just contact us, and we will gladly give you a new Aquarium Heater replacement. 12 Month Warranty and 24 Hour Professional After-sales Service.

Brand: PULACO


Special Feature: High Accuracy


Color: Transparent


Age Range (Description): Adult


Included Components: heater


Outer Material: Glass


Specification Met: CE


Display Type: Analog


Product Care Instructions: Wipe Clean


Unit Count: 1.0 Count


Product Dimensions ‏ : ‎ 5.5 x 1.2 x 2.7 inches; 4.23 ounces


Item model number ‏ : ‎ PL-168


Date First Available ‏ : ‎ November 18, 2019


Manufacturer ‏ : ‎ PULACO


Best Sellers Rank: #2,839 in Pet Supplies (See Top 100 in Pet Supplies) #4 in Aquarium Heaters


#4 in Aquarium Heaters:


Customer Reviews: 4.2 4.2 out of 5 stars (11,818)


Brand: PULACO


Special Feature: High Accuracy


Color: Transparent


Age Range (Description): Adult


Included Components: heater


Outer Material: Glass


Specification Met: CE


Display Type: Analog


Product Care Instructions: Wipe Clean


Unit Count: 1.0 Count


Power Source: Internal Power Source


Model Name: PL-168


Item Length: 4.9 Inches


Upper Temperature Rating: 93 Degrees Fahrenheit


Response Time: 500 Milliseconds


Reusability: Reusable


Immersion Depth: 12 Inches


Style: Classic


Indoor/Outdoor Usage: Indoor


UPC: 763032017889


Manufacturer: PULACO


Item Weight: 4.2 ounces


Item model number: PL-168


Date First Available: November 18, 2019


Item Package Dimensions L x W x H: 5.51 x 3.62 x 1.81 inches


Item Dimensions LxWxH: 5.5 x 1.2 x 2.7 inches


Brand Name: PULACO


Target Audience Keyword: fish


Directions: Adults 18 years and older


Warranty Description: 1 YEAR


Size: 25W up 1 to 6 Gallons


Number of Items: 1


Specific Uses for Product: fish tank heater


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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Top Amazon Reviews


  • Great product, perfect for what I need!
Size: 25W up 1 to 6 Gallons
I bought 2 of these and received them at the same time. 1 keeps the tank at 78 per the attached temp strip, the other keeps it at 76 per the attached temp strip but it is reading at the 77.7-79.6 when I temp the tanks with a thermometer. This is in range of what I need so it works perfect for me, both tanks are 2 gallons with a small amount of gravel in the bottom and I'm raising triops in them. ... show more
Reviewed in the United States on January 10, 2026 by Bethany

  • Easy to set up and reliable
Size: 25W up 1 to 6 Gallons
I’ve been using this heater for my aquarium plants, and it works really well! It’s small, easy to install, and keeps the water at a steady, consistent temperature, which is exactly what my plants need to thrive. The free thermometer strip is a nice bonus, making it simple to check the temperature at a glance. It’s quiet, reliable, and I feel confident that my aquarium stays safe and healthy with this little heater in place. ... show more
Reviewed in the United States on December 22, 2025 by Debbie

  • SATISFACTION GUARANTEED!
Size: 25W up 1 to 6 Gallons
First of all, I buy a LOT of STUFF on Amazon and I almost never give reviews. Why? Because I'd be spending an un-Godly amount of time just writing reviews so I skip it. However, I HAVE written reviews. What motivates me to write a review when usually I just SKIP IT? What motivates me is when I receive a product from a buyer on Amazon that blows my socks off and is BEYOND my expectations. I have bought many thermometers over my fish keeping years. Left the hobby for awhile (I should say, "Left the Lifestyle') & when I came back LO & BEHOLD, Nano Tanks are the rage. Nano tanks and I am very fond of planted glass bowls (I'm about to try a new Walstad bowl- CYS-EXCEL 13.5"h x 15.25" across on Amazon) Consequently, I have purchased many, many small heaters for my smaller glass bowl and a 7.11 gallon 11.8" x 11.8" x 11.8" Landan Nano Cube (Amazon) in which I wanted a small heater that couldn't be seen. ALL the small heaters I tried were failures at maintaining the status quo temp I was seeking. They couldn't hold 78°F water temp. no matter how small the aquarium / bowl. So I had this big-ass honkin' heater in my 11.8" cube and THAT did a great job but too bad it's HUGE and is easily seen as a big ass THINGY in my cube. I stopped heating the bowl. The little Nano heaters I was buying for the bowl couldn't even maintain my bowl temp. and that was my small bowl at about 2.5-3 gals. Now I just bought the larger 4 gallon bowl and it LOOKS Huge but still small relative to the cube. So I'm thinking...I better look HARDER for a good mini-heater and I landed on this PULACO 25W heater. One of my criteria for buying on Amazon are the reviews. Not just written review content but HOW MANY reviews the item has. The PULACO 25W heater has over 10,500+ reviews! WHAT!? Now, I'm interested! It's PRE-SET to 78°F so that's what I want in my Nano and my bowl. If you have a situation where you are keeping animals or plants where you want it warmer or cooler i.e. you don't want 78°F. Then this is NOT the heater for you. Seventy-Eight Degrees. That's it. But it's a reliable 78°F and I check it regularly two different ways. You will actually receive a small 'Stick On The Side' thermometer which I stuck on the Nano side wall. I also bought an Etekcity Infrared Temp Gun (Amazon) which I take temps of everything. I heat replacement water for my Nano tank up to the current temp and I'm taking their temps with the Infrared gun. Both the cheap 'stick on' sticker and the Infrared gun confirm---> 78°F !!!! I was shocked and surprised that this little guy...the PULACO 25W Small Aquarium Betta Heater with Free Thermometer Strip did EXACTLY what it was advertised to do. Heats water up to 78°F and holds it steady at that temp. I even experimented by using it for a week in the 7 gal. Nano and it held 78°F as advertised. So, despite it's diminutive size which I LOVE LOVE LOVE it's only supposed to be rated up to 6 gallons. To be honest, my Nano probably has 6 gal. in it once I subtract the substrate, the hardscape, the plants, etc. Anyway this little PULACO 25W is also a PLUG 'N PLAY. All you do is plug it in! It's easy to use and you can easily hide it for your viewing pleasure! I just want to comment on the negative reviews. I know that there is mixed feedback on durability, performance, quality heating value (whatever the definition of THAT is!) but I have not had an issue and I've been using the hell out of it for two months. I don't understand the complaints about glass breaking? Now, I haven't been rough with this PULACO 25W glass heater, I haven't bumped it against the aquarium or bowl. I believe that ALL GLASS HEATERS are prone to breakage (especially if you have some age on that glass heater!) and YES, I believe you could break this little PULACO with the wrong move (glass is breakable!) but I find it hard to believe that the glass would break with normal use. Just sayin'...how do you break a glass aquarium heater? It doesn't take much imagination to picture it breaking...now picture HOW it got broken. Another interesting aspect of this heater is that on my little 11.8" cube (about 6 gals) I am running not one, but TWO EHEIM Canister filters. Both are the small EHEIMs (Filter 2211 -'Classic 150') but still... I am moving a LOT of water using two EHEIM Canisters on that little cube but that little PULACO 25W handles it, keeping the water at 78°F even though I am moving so much water through the two canisters. I think that it's not only interesting but important to know that the little heater is a solid choice. LAST BUT NOT LEAST----> remember my headline? SATISFACTION GUARANTEED! Here is your promise from the manufacturer: ★【SATISFACTION GUARANTEED】Our Aquarium Heater is built with durability in mind and safety for every design. In the remote possibility that you’re not satisfied with our product, just contact us, and we will gladly give you a new Aquarium Heater replacement. 12 Month Warranty and 24 Hour Professional After-sales Service. And, of course, if you find that you don't like it right away, return to Amazon for your refund. And NO, I don't work for the PULACO people in any way, shape, or form. Out of all the crap I buy on Amazon, I write this because it's a product that I believe in and I have run the gamut of small heaters, all the rest failures. ... show more
Reviewed in the United States on July 2, 2024 by Bobby Magic

  • This heater murdered my Betta. Amazon needs to pull this product.
Size: 25W up 1 to 6 Gallons
I bought this heater because it was explicitly advertised as being safe for Betta fish. It is not. This heater overheated my tank and murdered my Betta. The tank size was appropriate, the heater was fully submerged, and I followed the instructions exactly. The temperature climbed far beyond a safe range, and by the time I caught it, the damage was done. What makes this worse is that after my fish died, I read further down the reviews. At first glance, the reviews look fine. But if you actually read past the top few, it is the same story over and over. Overheating. No temperature control. Dead fish. I usually do a good job reading reviews, and I regret trusting the “Betta safe” labeling on this product. A heater marketed for Betta fish should be one of the safest pieces of equipment you can buy. Instead, this product creates a lethal environment. A heater without reliable temperature regulation is not just defective, it is dangerous. Amazon should do something about this. This product should not be sold as Betta safe, and at a minimum, Amazon should refund or replace not only the heater but also the cost of the fish it killed. If you care about your fish, do not buy this heater. ... show more
Reviewed in the United States on February 9, 2026 by Jacob Ventura Krekorian

  • Worked well until it didn’t
Size: 25W up 1 to 6 Gallons
Not the greatest mini heater, but cheap enough that I got what I expected out of it. It lasted about a year before it crapped out on me. During that time, though, it worked very well, maintaining a consistent temperature in a 5 gallon mini tank for the full year with barely any maintenance. What eventually happened was that the glass housing separated from the rubber on top and it became waterlogged, which ruined the electrical components. It no longer worked at all after that and I just chucked it in the trash. For just ten bucks (I think that’s how much I paid for it), I don’t consider it a big loss, however ... show more
Reviewed in the United States on October 27, 2025 by Anthony Carabello

  • Heater is keeping my fish cozy! 5 stars!
Size: 25W up 1 to 6 Gallons
My fish, Bella, says thank you for this amazing heater. It works great, easy installation, and easy to clean! The only complaint is that the temperature sticker is hard to read. Don’t love this but the main reason I got this was for the heater and that is 5 stars!
Reviewed in the United States on February 3, 2026 by jd

  • Works great
Size: 25W up 1 to 6 Gallons
So far functioning well, but the temperature actually stays at around 77 Fahrenheit on my 5 gallon, I’m overall happy with my purchase.
Reviewed in the United States on March 3, 2026 by LacyG

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