Aqueon Small Aquarium Fish Tank Submersible Mini Flat Heater Up to 2 5 to 5 Gallon Aquariums 7

I was hesitant based on the reviews but decided to get it anyways as I love the flat design. I have a 5 gal tank and this little heater raised the water temp from 71F to 78F, which is exactly what I needed. I do have the heater placed near my filter so it gets good water flow around it, not sure if that matters or not. It is a heater that is on all the time, so you will need to monitor the tank temp so it doesn't get too cold/hot. Read more

This is the perfect size for my betta tank. Works great!! I paired it with a thermometer and it holds steady at the perfect temperature. Read more

1. WHY I GOT THIS: Needed a compact, reliable heater for a small fish tank. I wanted something easy to use, that wouldn’t overheat, and could keep the water temperature stable for my fish. 2. DID IT WORK? Yes! It heats consistently and keeps the water at a steady temperature. However, it’s not adjustable, so it maintains a preset temp—something to keep in mind if you need precise control. 3. WHAT I LIKED: ✔ Compact & unobtrusive – Doesn’t take up much space in the tank. ✔ Plug-and-play setup – No buttons or dials, just drop it in and it works. ✔ Reliable for small tanks – Keeps water temperature stable in a 2-5 gallon setup. 4. WHAT COULD BE BETTER: 🔹 Not adjustable – You’re stuck with the preset temp, which might not work for all fish species. 🔹 Might struggle in colder rooms – If your house gets really chilly, this may not provide enough heat for larger tanks. 5. FINAL THOUGHTS: If you need a simple, no-fuss heater for a small aquarium, this does the job well. Just be aware that it’s not adjustable, so if you need precise control, you might want a different model. Read more

I needed a heater for my little 2.5 aqueon aquarium that I grow aquatic plants in. I tried another product first that sold itself as for tiny tanks, but it heated the water up to close to 100 degrees F, so I returned that one and purchased this heater. This heater does the job fairly well. It's a bit bulky for a 2.5 gallon tank, but the temperature sits right where I want it to -- just a bit over room temperature. If you're looking for something with more precision and control, this probably isn't the right product, but honestly for a tiny tank, it's going to be pretty rough to get your temperatures exact without an excessive amount of work or money. For something that provides just a bit more heat without going overboard, this heater is perfect, especially for the price. Read more

I followed the directions and have experience with aquarium heaters but this one just doesn't work. I let it sit in the tank all day in case it was just incredibly slow to warm, but there was no difference in temperature by the end of the day. I'd be willing to try again with a new unit but it's not financially prudent for me to return it. It may be unfair to mention here as it's probably Amazons responsibility, but I want to warn people who may be in a similar position - I don't drive or live near any free drop off points. That leaves me to either: pay to get to a free drop off center, pay $6.99 to leave it at the closest place to me or have it picked up, or just eat the cost and throw it out. It wasn't a very costly item, but it's still an unfair situation and unfortunately leaves me with a bad impression of the brand/product. Read more

It only increases the temperature by a few degrees, so the water temperature fluctuates with the room temperature. Read more

Everything about this purchase had me hesitant. But I bought it anyway, after all I had already lost $25 and 2 fish in my Aqueon 3 gallon cube. At first I thought ok its been 16 hours and I'm up to 75.4 lol 😆 then I was like o well it's still cycling I will check back. Now we're on day 3 and I have checked this temp multiple times and it's exactly 78.1 degrees F. Therefore I have come to the conclusion that it does as it says. Yes it is preset but if you plan to just do plants and maybe a Betta you'll be happy with this purchase. I also have the 3 gallon filter they sell in the same tank. I traded the cartridge for a sponge and a spot for a carbon sponge. The Water is crystal clear and close to being ready for plants and a fish!!!! Read more

This heater, unlike others of its size, keeps the tank a steady temp and does not need to be unplugged and plugged back in constantly to maintain the proper temp for the tank. I purchased another cheaper brand from Walmart and hated it. I'm so so glad I got this one for my daughter's Betta fish, because they enjoy their water to be between 75° and 82° F. This heater automatically keeps the temp between 76° and 78° Fahrenheit with little fluctuation. The only time the temp drops is when the room temp drops dramatically. When the ambient room temp is steady, so is the temp the heater maintains the aquarium water. Really love this heater. I keep mine placed under and behind the filter in a 3.5 gal tank. Read more