Submersible Aquarium Heater, Adjustable Fish Tahk Heater with Free Thermometer Suitable for Marine Saltwater and Freshwater

I’ve been cycling my tank now for a week and a half and this heater works wonderfully. Super easy to use and assembly was also just as easy. It heats my 36 gallon very well and isn’t too obnoxious or large since I have mine situated right in the middle of my tank. Just a note for anyone looking: this product says you can submerse it sideways in the description. Honestly I think that is really stupid. I wouldn’t ever do that. I’m sure all the reviews that are saying it lights on fire had the cord part inside the water (aka sideways). I would also leave the adjuster part out of the water if possible. I don’t know, that’s just my dad’s old wisdom talking. Just use it vertical. It works literally the same. This is such a great product. I really recommend it a lot. Great value for money and works just as described. Ready to use out of the box.

Works amazing and you just can’t beat the price. Keeps my tank at a consistent temperature and it’s easy to install and work. No noise or anything weird. It does seem like a very fragile glass and you have to be very careful when handling. Overall love it.

I purchased this heater as a replacement since my last heater finally gave out. The heater itself does its job, it heats the water to temp and keeps it somewhat to where it’s set. It was a great addition having the temp probe and digital readout. I have tested it against another heater’s internal control and mercury thermometer and it seems to be mostly accurate. My only issue, and reason for giving this thermometer a four star review, is because the temperature dial on the top of the heater, are the ONLY temperatures you may choose to heat your aquarium. It is not variable, or adjustable. I found if I set the heater to 75, the tank would sit around 72, and if set to 79, it will stay at 79. The seven degree swing seemed rather large IMO. Like I said, the temp is not variable, and if the selector on the heater is not lined up with a number, the heater will not turn on at all or heat the aquarium. All in all it does its job, but if you want variability when selecting a temperature, spend a little extra money and buy a heater with that option.

So, I love this heater because it is sturdy, reliable, and keeps the water temperature nice and warm even when temperatures dip overnight. But most importantly, it's affordable. I'm a broke college student trying to take care of my only quarantine betta fish friend, so price and reliability is of utmost importance to me. That being said, this is a good heater, but it comes with some quirks. 1) The temperature dial is not accurate. This heater tends to run hotter than what it is set to, especially for smaller tanks. For example, right now in my 6 gallon I have it set to 73. This keeps it at 80 degrees consistently, all the time. Make sure you run tests to find out where the dial actually needs to be. I'm kind of used to doing this because most heaters I've found are not accurate in this regard. 2) I think the suction cups are wearing away over time. Hasn't been too much of an issue yet (had these heaters for almost a year now) Quirks aside, for the price I feel you can't beat it and I've been really happy with it so far. Just be cautious and test your equipment before trusting it with live fish in the tank. Same goes for the extra thermometer. I don't really trust these digital ones so I frequently test them with other submersed type thermometers to check them. So far they've tested accurately for me. I mostly use these digital ones when I am acclimating fish to check that the tank/bag temperature matches up.

Why buy such an expansion heater, when you can buy this one! It works great! Size is perfect! My fish are very happy! I have had it for a little over a month now and it’s still holding strong! Easy to use and set up!

This heater is packaged nicely and works great so far. Seems to be accurate and comes with a stick on thermometer that is accurate and a hand held LCD thermometer. Pleasantly suprised with the quality at this price, hopefully it lasts me a while.

The temperature doesn't regulate correctly and the dial isn't accurate. The heater's durability is concerning, with concern for my betta fish health is also mixed, with I don’t want this to kill my betta fish with the fluctuation, it’s a good value for the money. Not my fish life! Now I need to find a reliable replacement before it breaks and definitely kills my baby girl betta.

Low maintenance heater. Durable over time. Maintains set temp range very consistently with minimal adjustments. Low price for good quality. I’d purchase this brand again. Adjustment knob is a few degrees off from the actual water temp. You have to adjust it a bit over the course of a day or two and compare it to thermometer to find the water temp you’re aiming for. Once it’s set, however, it maintains water temp reliably and consistently with hardly any maintenance Other than that, it works fine. No problems

Nice looking, solid unit. 100W works well in my 20g tank. Tank is in a coldish bedroom and it brought up the temp ~15 degrees F quickly. The separate temp gauge is really handy, almost worth the price alone. Probably will order another unit soon to replace an old one on another tank. (Update - I still like the heater but I think the separate temp gauge isn't accurate - reads higher than two other units I tried)

Well I was very pleasantly surprised on how well this heater works. I did intentionally set my dial at least 5 degrees lower than my target temperature. It didn't take long to bring up to my intended target reading. Also it's definitely a plus in which this order came with a mini digital thermometer which seems to work very well. I certainly will consider this item for repurchase in foreseeable future needs.

It works, what else can I say? The dial on top to control the desired temperature was definitely the highlight! It's as easy as submerge, plug and turn the knob. It comes with a temperature monitor too and that's such a great bonus! For the price and quality, i don't see anything better.

The heater with it's thermostat work well, but unfortunately keeping the temperature in sync is a problem. We have adjusted the temperature over the past few days either up or down because the thermometer doesn't read the correct temperature to the heater adjustment. Ex: I have it set at 80 and it's been 85.9, 84.7 etc jumping all over the place, So, that is my reason for not giving a 5 star overall rating. We will continue to monitor to see how it performs, but with that in mind, it looks extremely more expensive than what I paid.

Not sure what happened but in less than a year of use, the heater has started randomly getting super hot to the touch. Decided to take it out in fear of it burning my fish