SZELAM 25W Smart Mini Aquarium Heater, Betta Fish Tank Heater Thermostat Warmer Submersible Anti-Explosion/Energy-efficient Water Temp Controller

We got a betta, and the pet store was amazingly uninformative. When we realized the poor little thing needed to be in warm water, we freaked out and got this heater with next day delivery. We put it in, and for a good long while it would not heat up the tank - at least not to the desired 78 degrees. It basically took a whole 24 hours to get there, so we were quite concerned. Now that it's reached that temperature, I'm going to see if it stays more or less there, or if it becomes too hot (hope not!), but so far - it seems fine.The unit is super easy to install, the suction cups work great: while finding a good spot, I did have one of the suction cups come off, but it was super easy to slip it back into place and carry on. The two plants (I thought it was supposed to be three?) are not really important, but they are cute, and my son was very happy to add 'decorations' :) while my mom wondered why they weren't green - hahaha!The pic is of when we initially put it in and the temp wouldn't budge past 72 degrees for a good long while. After some additional questioning at the pet store, it seems that the betta's range is 72 - 82 degrees, anyway - so... in theory he should have been comfortable since we put it in (in reality, he went and snuggled up against that thing until the rest of the tank warmed up! poor fish... )

It worked for awhile then suddenly stopped working. It no longer heats the water and I had to buy a new one.

Very slim design. Even in my small, round tank it almost disappears. The indicator light is a reassuring feature. I love that I can glance at the temp and know what the heater is doing because of the light. My fish is indifferent to it. He fights with the glass thermometer...but he's fine with the heater. Also it hugs the glass so no chance of him getting caught in any way.This is a review for the heater, but also something I learned the hard way and I hope someone can glean something here. I have a 3.3 gal round Topfin Bettaflo tank. It's 10 inches tall and 10 inches at the widest point. The filter is a substrate, the return tower comes right up the middle of the tank, so there isn't a whole lot of interior room. The thing is, heat doesn't radiate out thru the glass. So when the lid is on, it's like a thermos inside and the temp climbed to 86° with my previously purchased 15 watt heater from Petsmart. That's only a few degrees away from a cooked fishy. I honestly thought fish tanks were supposed to be relaxing. This tank stresses me out because of the difficulty maintaining the temp. It's like the glass is LowE because a stick on thermometer won't read any temperature. As far as the heater itself, it's awesome and after a few days of regulation, it now keeps my tank at a steady 82 degrees. A definite reccomend!!

My old bulky heater for my 5.5 gallon tank finally died so I was look for a reasonably priced replacement and I liked the small footprint this one had. I read the many reviews...some not so good. I took a chance on it and it’s working wonderfully. I got the 25 watt and it keeps my tank between 78-80 degrees without me having to adjust anything. It’s only been a few days so if it goes crazy and stops working or cooks my tank I will update but it’s working just fine. I will say to give it some time after you put it in. It took a few hours before I felt like it really started to warm the tank slowly. It probably didn’t help that I kept moving it around trying to decide where to place it. It’s a great slim heater that doesn’t take up a ton of room and my fish seem very happy (I’m not sure what that even means...they’re swimming around eating and don’t look lethargic or like they’re dying I guess haha) Anyhow it was a nice cheap replacement that doesn’t take up much room 👍🏻

I installed the SZELAM 25W Smart Mini Aquarium Heater in our 5 gallon Betta fish aquarium. Shortly after turning it on the red light illuminated. The tank temperature showed 69F on our aquarium submersible mercury thermometer. I checked it over the next hour or so and the light would go on an off from time to time but the temperature was clearly rising. By the next morning the tank registered 75F. It's not been about a week and the temperature is consistently 75F. While I suspect that in a smaller tank you'd probably see a slightly higher temperature and in a larger tank a little lower temperature being maintained, it's right in the comfortable ranlge for Betta fish for us and is working perfectly. Our Betta fish is a lot more active not too - so he appears to be enjoying the warmer water :)

First of all, I'm a first time Betta owner and I have a 5 gal. tank. I bought this heater and it was a great buy for the money but the past few days I've noticed the red light (for heating) is always on and the temperature is no longer in the ideal range. I'm worried about my little guy in there! Trying to decide if I should get another one or go with something different? I mean for $11 bucks ($8 at the time) it's been a pretty dang good heater but I can't take any chances with my baby boy in there. :-( Temps. are dropping as Fall is coming....gotta have a reliable heater.

Works great for my little betta tank

I have a 1.5 Gallon tank for my Beta that I bought at Walmart. I keep my house at 65-72 degrees which is too cold for his water seeing as he is a Tropical Fish. Plus I have 3 Ghost Shrimp in his tank with him. They’re also tropical so I was looking for a heater that would do the job and this is it! As soon as I put it in and it showed the red light for heating up he stayed right by the heater. Now every time the red light comes on he swims to it and stays near it until it’s done and his water is significantly warmer. Keep in mind you will see condensation on the inside of the tank where the water isn’t if your house is colder than the water in the tank. Also, this won’t work for a bowl or anything shaped like a globe Bc the heater is straight up and down about 5-6 inches tall. But it works perfect for my little betta

I got this for my 1.1 gallon tank. Put it into 71 degree water and within an hour, it was up to 80. Unfortunately, in that small tank, it didn’t stop there. I had to keep unplugging it because it consistently over heated the tank to 84-85 degrees. This was a pain because the water would then cool off quickly when I unplugged it - not ideal for fishy. Plus, I couldn’t leave it plugged I overnight for fear of cooking the fish, so the water temp would really drop overnight to high 60s (Canadian winter makes for a cold house at night). I upgraded to a 3 gallon tank and, yay!!, the heater keeps that tank at a constant 80-81 degrees. My fish loves it. When the red light comes on, indicating that it’s throwing off some heat, he swims over and snuggles up to it. The suction cups are amazing. I’m even able to mount it to the curved wall of my half moon shaped tank. I love this because it did look kind of obnoxious with the white print all over it, when stuck to the back wall of my tank. Really pleased with this purchase. It was just too much heater for my smaller tank.

I put mine in a 3 gallon nano tank. It keeps the tank at 78. There is no way to set the temp which I don’t like. The other think is the white text on the show face. It blends nicely except for the text. For the price it’s ok.edit: the temp fluctuates and is now set to 84. Having no control is not a good thing.

The media could not be loaded.  Perfect for our little work buddy, we weren't sure if the water was staying warm enough in a big open area his tank sits. Within the first day the heater was installed, he is much more active than he used to be. Do not make the mistake my coworker did of plugging it in BEFORE installing it (Instructions specify this but he learned the hard way) haha. The little plants that came with are super cute too! We added the blue/purple one and it looks great!

This heater does as advertises. I have a 5 Gallon tank and been using this heater for over a month. The temperature in the main part of the Tank maintains itself around 75-76F, but that is because I have installed the heater in the back compartment (which is not recommended). The back compartment of the tank stays at a steady 78F. If I could better circulate that part of the tank I'm sure the whole tank would maintain a 78F Temp.Great value!

I was concerned about getting this due to the reviews. Truth is I think I've only had it for a month but it's so compact that it's perfect for my needs. I have a top fin retreat and this product was perfect to fit inside the built in filter.I'm hoping that this guy will last me years but I guess time will only tell. Every now and then I check to see if the light goes on to see if the heater is working.