Features:

  • Fully submersible compact heater
  • Reliable performance; Maintains set temperature of 78 degrees Fahrenheit
  • Suitable for fresh or saltwater aquariums
  • Made of durable polymer
  • Ideal for aquariums up to 2.65 gallons; 2-year warranty
  • Heater was designed to reach and maintain the set temperature of 26ºC (78ºF), provided that the maximum difference between the ambient and set temperature is less than 5ºC (9ºF)
Really Happy

In my opinion, a preset aquarium heater is a one or five-star product. It either works well or not at all. That said, I'd go for five here. I'm running this on a small 2-gallon betta tank and wouldn't put it on anything bigger. During the winter, I keep my house at 66 degrees. This little heater keeps the water at a relatively constant 76 degrees. It does seem to be on "a lot" though, hence why I said that 2 gallons is about the max it will handle. Build-quality seems really quite good. Its metal housing feels robust and for being so small, it has a bit of weight to it. For a tiny tank, I would definitely buy again. ***My Rating Criteria*** Build Quality(47.5%) - 5.0 Stars Efficacy(47.5%) - 5.0 Stars Post-Sale Support(0.0%) - n/a Packaging/Presentation(5.0%) - 3.0 Stars WEIGHTED AVERAGE(100.0%) - 4.9 STARS

Using in a 2.5 gallon glass Top Fin aquarium for shrimp

After researching low wattage heaters for small aquariums I landed on the Marina 10-watt heater. And I'm glad I did. I put this in a glass 2.5 gallon Top Fin Retreat Aquarium that I'm cycling for shrimp. The heater fit great, fully submerged, to the right of the pump, opposite the filter in the back of the aquarium. After 3 days the temperature has been a constant 74F, which is in a good range for shrimp (from what I've read). I was hoping water temperature would be a little cooler than 78F and it is. Factors such as heater location placement in tank, ambient room temperature, tank volume, or thermometer accuracy will most likely affect a very minimal temperature reading fluctuation. Prior to plugging in I let the thermometer acclimate to the unheated tank temperature, per the instructions. So far, this little, well built heater is working just great in a room with indirect sunlight that is usually around 60F.

10-watt heater works great in a one quart aquarium

Okay. It took me a long time to finally decide but I'm happy I bought these 10-watt compact heaters. I've got two bettas. Each is in a one quart aquarium. Our house temperature drops to 60 degrees at night. During the day it gets up to 70 degrees but this winter is quite cold and my bettas were not looking too happy. My bettas looked like they were in hibernation before getting these 10-watt heaters. Listless and not eating much at all. I also purchased these thermometers on Amazon: Marina Floating Thermometer with Suction Cup. I received brand new heaters so that was good. The cord is more than sufficient in length to reach the electrical outlet with ease. The heater is preset to turn on/off automatically. It's holding the temperature right in the middle of the green markings on the Marina Floating Thermometer with Suction Cup. No problem with boiling my bettas or with a heater that doesn't heat. The heater maintains the temperature very well and turns on/off without any plugging/unplugging necessary. After 3 days, my two bettas are active, energetic, and eating well again. This 10-watt heater has a 2-year warranty. It is a good product. Does what it says its will do.. It works great. As I mentioned before, my bettas are each in a one quart aquarium so don't hesitate to purchase if you have a small desktop aquarium. The heater is barely completely submerged in my aquarium as it is 4 inches long but it is fully submerged and is functioning as described. I heartily recommend these heaters for small aquariums,

This heater is perfect for the DeepBlue 5B model tank.

I am a young hobbiest and I thought I needed a good heater for my new fry grow-out mircro aquarium. This heater was the one after meticulous reading and comparing. The heater arrived a day or less behind schedule according to the notifications that came to my phone. However it was still a timely delivery. After I unpackaged the heater it was exactly as described and absolutely *perfect* for my “DeepBlue 5B 2.3g” aquarium! I hope that it works well for the two years it warrantied for and it keep my tank adequately heated.

Perfect for Small Tank

I bought this for my 3 gallon beta tank. It's only about the length of your hand, so it doesn't take up much room at all, which makes it perfect for a small tank. It wouldn't work for a big tank, it took the heater about 5 hrs to bring my little tank up to temp (it's winter, the tank sits by a window, so water started out very cold). The fish are def much happier.

Works well in a 3 gallon acrylic aquarium

Reall happy with this purchase. I have a small, 3 gallon acrylic tank and had been using the under-gravel heaters in the past. I didn't like the sight of the electric cord up the back of the tank, even mostly hidden by plants - just looked shabby. The last under-gravel heater died, which I discovered when my betta became very lethargic - I hadn't checked the thermometer on the side of the tank for a while - he was cold! I purchased this heater and installed it in the back corner of the tank, next to the intake valve - looks good and blends in - neat and tidy. It's winter, and my house fluxuates between 63 at night to 67-68 during the day. The heater maintains the temp at 76, without fail. Happy with my purchase, and hope it lasts a while. Highly recommend for a small tank. Sounds like there may be some quality control issues since several folks have noted that their heater wasn't heating adequately. Call or 'live chat' with Amazon folks - they will quickly replace or refund for items that don't work like they're supposed to!

Used this for heating water outside during the winter. Perfect for small animal use - chickens, rabbits, feral cats etc.

I used this to heat an open water 2 quart bowl of water outdoors for my chickens during the winter (I live in New York right outside NYC). This was the perfect wattage to keep the water liquid but also keep it at a reasonable temperature for my chickens to drink but also to not have the water be too warm. What was critical was that it's unbreakable (chickens are NOT graceful and if they can break/knock something over/trip over it etc. , they will). I didn't need any fires or electrocutions and this heater fit the bill perfectly. It's fully encased in a plastic/rubberized layer so won't break. Also the bowl ran below the heater level a couple times with no damage to the heater. Would definitely recommend. If you take care of feral cats, this would also be perfect to make sure they have an ice-free drinking source.

These work just fine. Misunderstood by many reviewers.

Unobtrusive. Simple. As advertised. Just to be clear, and to clarify what may be a simple misunderstanding of how these things work: The heater has a built-in thermostat that is set to about 78F. It controls the heat of the heater, not the heat of the water. If functioning correctly it will not raise the water temperature above that heater setpoint. If your aquarium overheats it's either a broken heater or your room is hotter than 78F (or something else is heating up your water. UV sterilizers, for example, can heat the water going through them by a degree or two.). If your tank won't get to 78F it's because the heater is broken, or the one chosen isn't powerful enough for the size of your tank, or your ambient air temperature is too low. These heaters are rated for a size range (gallons) just as a rough indication of typical expected application. When they say that the heater, for example, will raise the temperature up to 4 degrees, and is rated for 1-4 gallons, what they are saying is that for the largest size tank (4gal) the heater should be able to handle an ambient temperature of 74F and raise it 4 degrees to 78F. Smaller tanks can deal with lower ambient temperatures. But this can't be "exact", can it? They don't know if there's a breeze blowing on your tank, if it sits in the direct sunshine, what the surface area to volume ratio is, and other factors which can effect how much heating Wattage you will actually need. And there's a reason they don't just measure and regulate the temperature of the water instead of the heater itself. It's not trivial to stabilize a feedback loop that can have an unknown and/or unstable feedback time delay. Depending on how far from the heater the sensor is placed, what the water currents are, and other "stuff", your tank would probably end up going through non-optimal temperature swings. These heaters (and I mean all sizes and brands) are what they are. Not really a problem. Just deal with it.

Great little heater!!

This is a great little heater for my 3 gallon guppy tank!! For some reason, they’re tank felt like it was freezing every morning when I would check on it so I’d have to ad a little hot water to make room temp. I put this thing in around 10pm the night before, woke up next morning to check on fish and they were in they’re glory swimming around so happy in warmer temp water.. easy to use, just put in water (unplugged) and let alkaline and sit for about 10-15 mins then plug in and your good to go. Will def purchase another one for my other guppy tank need be! 2 year warranty!!

Works as described

This heater has been keeping my 2.5 gallon tank at a steady 78° since I put it in three days ago. It’s not adjustable - it simply turns on when the water temperature goes below 78° and turns off if it gets any warmer. The light turns on when it’s heating and off when the tank is at the correct temperature. I have it fully submerged by the outflow of the filter to properly disperse the heat throughtout the tank and avoid “hot spots.” I researched many different heaters before buying this one. There are so many terrible stories and negative reviews about aquarium heaters malfunctioning - either not working well enough or overheating and harming fish. This one is working fine so far and I will update this review if I gave any problems with it.

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