Cobalt AquaticsNeo-Therm Pro Aquarium Heater 25W - Submersible, Accurate ±0.5°F Electronic Thermostat, Shatterproof for Freshwater & Saltwater Tanks

I was looking for a heater for my new 2.6 gallon tank but every heater I found either had horrible reviews or weren't adjustable and people said with such a small tank it would cook my fish. When I stumbled upon this heater I was impressed with all of the glowing reviews and everyone saying it not only maintains the water temperature by it actually heats the water. A lot of reviews for other heaters said the heaters only maintained temperature, it didn't raise the temperature. I couldn't ignore all of these reviews, obviously this heater does something right so I ordered one.I just got this heater today and so far it seems to be working perfectly, a little too perfectly as it seems to be warming the water 2 degrees higher than what I set it at (this is confirmed not only with a separate thermometer but also by the heater itself) but this is no big deal, I just set the heater 2 degrees colder than I want.The heater is very slim and not too long, it fits perfectly even in a fairly small tank like mine. I didn't realize when I ordered it that it also acts as a thermometer but the way it's situated in my tank makes it really cumbersome to use it for that purpose (which is no fault of the product itself) so I still rely on a standalone thermometer for that purpose. Both the standalone thermometer and this heater show the same temperature so I'd say this is fairly accurate as well.The only complaint I have is something another reviewer mentioned; the suction cups don't work at all. I push the heater where the suction cups are against the side of the tank and they'll stick but then I'll check the heater a few minutes later and the suction cups have failed. I have no idea if the suction cups just aren't very good or if they're not meant to work on the type of surface I am sticking them to, it's like frosted glass or acrylic, not sure on that. However this isn't a big deal for me personally because the heater itself is situated in a small chamber so it doesn't really move much anyways but if it wasn't I would be worried that the heater might float on its side towards the top of the tank which the instructions say is bad.Overall I am very satisfied with the product and would highly recommend it. Sure it's a bit pricey but then again you get what you pay for. Instead of buying a sub par 10 dollar heater that won't work very well put another 20 dollars towards your purchase and buy this high quality heater.

With fall in full swing and winter rearing it's ugly head, I needed a good heater and fast. Past experiences suggest smaller "generic" beta type heaters can't heat up your tank enough, or worse tends to over heat when your room temp is warm(er).This Cobalt Neo-Therm Heater is as rock steady as you can get! Especially living in a cooler climate. Granted, there are some con's to this device. However, the pro's out weigh the cons.I currently have the  Aqueon Mini Bow 5 Desktop Aquarium . You know, with the built in filter just under the light hood fixture? And this heater sits up and down on the right side corner. It does take up a little space, but it isn't much at all.And honestly, I think it looks like it takes up much more, because the device is long and square-go-like. And when adding the suction cups and bracket system, it sticks out a wee bit more and looks bulky. Plus, with a "bow-front" viewing area and the device being under water, it naturally looks bigger than it really is.But again, isn't bad and a small sacrifice considering the desired goal of temperature.Truth be told, it will fluctuate a few degree's if you live in a cooler region of the country / world. But I still have my box-fan blowing and window cracked a bit at night here at 6,500 ft above the sea. In the mornings, the Cobalt display registers at least 4 or 5 degrees under the temp I set at 82 degrees. But I know once I close this window for the winter, I don't believe I will see these numbers changing much, if at all.Don't be a cheap skate! It's worth the cost if your running a small tank. I am using the lowest watt Cobalt of the line at 25watts. I considered buying the next step in watts above this, but I think I made the right call. And my beta "Mr. Snerdly" is as happy as can be.Pro's:Rock solid tempThin flat designNifty bracket system w/ 2 suction cupsEasy to read LED displayCon's:Long and obviousWill fluctuate "IF" you're in a cold region.

Loved all the features and small design about this. Great display, easy to set, temperature stability.. Except, it broke within 2 weeks. Thankfully, I use a separate temperature gauge to check and had a old emergency heater in the cupboard.

This Cobalt heater has a very small footprint and the accuracy is superb. I said it at 78° f and when I test it using a Hannah temperature probe it is reading 77.9° f consistently overnight. In the middle of the afternoon after the lights have been on for around 5 hours the temperature will go up to around 78.3 and hold. I'm only giving it a three-star rating in value for your money because this heater is damn expensive but it's money well spent if you want to keep your reef tank at a constant stable temperature. The cable is nice and flexible and the brackets is well designed. There's one other company that makes this style of heater and it is twice as long as the Cobalt and is nowhere near precise, and customer service for that other brand is non-existent. All in all you can't go wrong with this specific heater and being electronic it picks up temperature changes very quickly especially if you add room temperature water to your sump the units will start flashing and heat itself up. The seller was great and replied in reasonable time and the heater arrived before it's set date which was a bonus.

It works! And it is very sturdy! Easy to use! Would have no hesitation in recommending this product to other pet fish keepers.

Muy buen producto, ya que los calentadores de acuario generalmente están hechos de cristal, lo cual los hace fragil al impacto. Este calentador está hecho de un material a prueba de impacto, lo cual, dependiendo de tus necesidades, puede ser una mejor opción.Lo utilizo para el acuario de mi tortuga, la cual ha reventado calentadores de cristal. Hasta la fecha, el producto funciona sin contratiempos.La temperatura está expresada en Fahrenheit

LOOKS TERRIFIC, GREAT STYLE; LIGHTS CAME ON AND FLASHED ABOUT BUT IT DID NOT WORK AT ALL DESPITE NUMEROUS ATTEMPTS BE SEVERAL PERSONS!! THE TEMPERATURE NEVER CHANGED!!I WANT MY MONEY BACK!!!