Features:

  • Super-flat design. Fully submersible, modern design for energy efficient Aquarium and terrarium heating. Includes reversible holster/bracket, which allows heater to face inward or outward. See the product images to determine the best neo-therm size for your tank.
  • Accurate, one-touch system. Simply set temperature between 66-96°f with one touch and the neo-therm electronic thermostat will maintain Tank temperature within +0.5°F. Led displays both set temp and actual temp, simultaneously.
  • Ultimate safety and reliability. Integrated thermal protection circuitry prevents heater from overheating. If you forget to turn it off, the neo-therm will automatically shut it down.
  • Virtually indestructible. Unlike cheap, glass heaters, the neo-therm is a resin/thermoplastic heater with a shatterproof outer-casing. Made in Poland and includes a 3-year warranty.
  • Manufacturer You can trust. Most manufacturers rate their heaters on the ability to raise an aquarium 2-3°f above ambient temperatures. This is unreliable and misleading, as the average home fluctuates 2-3°f or more throughout the day. Cobalt rates The neo-therm on the ability to raise a tank 11°f above ambient temperatures, so you will never have to worry about overworking the neo-therm or it keeping up!
BUY THIS AND DO NOT HESITATE

Well here you are reading this. Doing your homework. And I know what you're thinking-why should I buy this when the glass Hydor Theos are literally less than 1/3 of the price? And will this fit in the pump chamber of my Spec V? The answer to the first is, because Hydors absolutely suck. Take it from me, I read the reviews and still tried them anyways to try and save a few bucks. Two of them. They fluctuate like CRAZY all day every day. And their thermostats fail, and when they do they fail in the - you guessed it, just like you've read - ON position. Not good for a fish tank. This is my second NeoTherm (25W for 3 gallon and 50W for my Spec V), and I couldn't be happier. Set it and forget it, maintains rock solid temperature range. Like +\- 0.2 degrees per my digital thermometer. Solid as hell, great product, great function, great warranty. I'll never try/buy another brand heater again. Just bite the bullet unless you want aggravation or to fry your fish.

One of the best

I've been in the aquarium world for many many years. For most of those years I've used the ehiem jager heaters. While they work great, they tend to be a bit bulky in a smaller tank. Looking for additional options I decided to take a chance on this heater. First, it came packaged in a Marineland filter box, confused at first, I opened it to find this heater nicely packaged inside. Weird shipping it in a different manfu box. Set up was easy, comes with two suction cups that actually work, I know right. crazy Setting the temp is easy, just push the button on top until the led rests on the number you want. I have this heater set to 76* for my betta. During the day time and night we kick the heater down pretty low. Even with the ambient temp in the house being between 65-67*, this tank still sits firmly at 76*. It's slim profile means you have more real estate room in your tank for scapes. These might be my new heater of choice going forward. If you are setting up a nano or 10g tank, this is the heater for you.

A Heater for the 21st Century

I've purchased a good number of aquarium heaters over the years and they were all variations of the same function and design, and has virtually remained unchanged for over five decades--a long tube, glass or plastic housing, with heating elements, which were then connected to some sort of thermostat circuitry. My last one, an Aqueon unit, malfunctioned and almost wiped out my whole tank's population because it overheated the aquarium and did not have a safety defeat mechanism. I lost 3 neon tetras, and two nerite snails in this incident and swore, (not verbally), that I would never use tube-type heaters again. Enter the Neo-Therm heater. I was struck by the new, sleek look; very modern and high tech. It wasn't a tube form factor, but was flat, which seems to provide more surface area to be in contact with the water. The LED readout is a great way to check on the water's temperature at a glance, and tells you whether you're up or down in the desired temperature you preset for the unit. One solid LED means your set temp and tank temp are the same. A flashing light before or after your set temp means it is higher or lower. To adjust the temp, you press a button located at the top of the heater, which is a bit difficult to push because it is small, and a bit slippery. But no biggie. Unlike tube type heaters, the numbers on the LED dial actually mean something, whereas, tube style heater numbers don't even correlate to the real temperatures at all, in most cases. All they do is act as a reference point for setting the temperature and this can be extremely inaccurate. I purchased the Neo-Therm and had it up and running in no time at all, not counting the recommended 15-minutes (or more) for the heater to calibrate itself when you first put it into your tank. After this I plugged it in and watched the LED dial display the water temperature. It already has a factory default temperature setting for 78 degrees F., so this makes it very easy to set up. This heater is solid-state, and according to the manufacturer, in the unlikely event that the unit fails, it will simply turn off, and not continue to heat the water. This feature alone makes the purchase worthwhile for me. The accuracy of the Neo-Therm is spot on as I verified the +/- 0.5 Fahrenheit degree accuracy of the unit with a digital thermometer. I was very impressed. The Neo-Therm is sturdy and the outer casing is made from shatter resistant plastic and should hold up for a very long time to bumps and bruises. There were a few issues though. The first unit I ordered was inaccurate to about 1-2 degrees and persisted in this false reading over two week's time. I return this unit, received a new one via Amazon's outstanding customer service, and the replacement unit is flawless. The second one is subjective and doesn't affect the Neo-Therm's functionality, but may be an issue for some. The temperature display numbers, which circle the LED readout from 66 to 96 degrees, are set in multiples of two, or in other words, all even numbers. So if your tank temperature is really 79 degrees F., the display will still show it as either 78 or 80, depending if it decides to round off up or down. So for OCD types, this may be a deal breaker. I've seen the Neo-Therm flash two numbers simultaneously, and perhaps this is the way it tries to show you the in-between numbers, but I only saw this happen once, and it happened with the unit that I returned, so it was probably a fluke. Maybe in the next software update, this could actually be a feature to show the "tweener" numbers. But outside of these two issues, I am very happy with the purchase. Yes, it is more expensive than other aquarium heaters, but if you total the cost of all the heaters you've bought over the years, and have failed or become inaccurate, this makes the Neo-Therm a bargain when you compare the price differentials and performance.

FINALLY! I DEFINITELY RECOMMEND THIS HEATER FOR 2.5 GALLON TANKS!

I've been looking for a good quality heater with temp control for my 2.5 gallon for over a year... I finally saw the 25W Cobalt heater (which is a higher wattage then I was looking for) for almost $50 and almost passed on it. I am so glad I didn't! Though it's a snug fit for my little 2.5 gallon, the heater is super slim and is only 6.5" long and fits in the aquarium at a slight angle, which is fine as the minimum water level is the top of the bezel (the round dial). I've only had this heater for two days, but it raised the temp in my tank from it's usual 72-74°F (with 10W Marineland heater) to 78°F within a few hours and only fluctuated about 1/2° overnight when we turn the heat off in the house. I couldn't be happier and will definitely update my review should anything go wrong. I DEFINITELY RECOMMEND THIS HEATER FOR 2.5 GALLON TANKS!

Best small-tank heater of several we've tried

We purchased the Cobalt Neo-Therm 25W heater for a 2.5 gallon Betta tank after trying at least three different heaters designed for small tanks. This is the only one we've been happy with. The smaller, non-adjustable heaters made the water too hot or made very little difference in temperature. We've had this heater for five days now and it is maintaining the temperature at a steady 78 degrees, day and night. It is fully submersible, meaning the entire unit, including the dial and some of the cord, is underwater. This heater fits horizontally into a glass rectangular 2.5 gallon tank, and would fit vertically into the other acrylic 2.5 gallon bowfront tanks we have. It is larger than the small useless heaters we tried in the past, so we applied dark privacy window film to the outside of the tank back and the heater doesn't visually stand out as much. The dial on the front of the unit is labeled in two degree increments with an indicator light above each label. The indicator above the current water temperature flashes; the indicator above your chosen setting (push the little button on top of the unit) holds steady. When the two are equal it is a steady light. Yes, it is comparatively expensive, but IT WORKS and I can go to sleep without worrying that my daughter will wake up to a fish fry. And the Betta is noticeably happier, swimming around and exploring instead of hiding on the bottom listless under his decorations. I'll be buying more of these heaters before winter for the other Betta tanks. (While the older 2.5 gallon Betta tanks use incandescent bulbs that add a few degrees when on, the newer tank uses an LED that doesn't add heat.)

Hi tech heater backed by very responsive support!

About two years ago I purchased this Neo-Therm 50 watt heater. It is incredibly easy to use - just press a button to select the temperature you want and two LEDs show the setting and current temp. Totally waterproof, and "set and forget" accurate. Well, set and forget until two years later when something went wrong and the temperature started to rise. I pulled out heater and the button was unresponsive. I unplugged, waited a bit and plugged back in, as others suggested. All seemed OK until a couple days later when the temp started to rise again. I took it out, put in my back up heater and looked up the warranty. The warranty was for 3 years, so I went online and entered my info, asking for help. Within an hour I had a friendly response back, saying they could help and asked for a picture of the heater and the receipt. I sent them in and almost as quickly, received another friendly response saying they would handle it from there. THE VERY SAME day I get notification that the replacement was shipped, along with another nice note saying how much they appreciate my business and "the least they can do is stand by their products." Wow - how often does that happen? Bottom line - high quality and easy to use product and you won't be left stranded if there's a problem. These guys have a customer service down pat and me a customer for life!

So far so good. I have has the thermometer a week now

***Update June 16, 2019*** I have this in an upgraded 6.5 Gallon Tank and it is working perfectly. Holding and adjusting Temp like a pro! ****UPDATE March 20, 2019***** Heater is still going strong and working perfectly! Highly recommend for anyone looking into a safe well made heater for a Fishtank between 2-6 Gallons! ************* So far so good. I have has the thermometer a week now. I have a 3.5 gallon 360* tank. I Have the temperature set to 76* it wavers between 76.4 and 77 depending on the flow of water from airstone and ambient room temperature. Super easy set up- You just set the temp you want your water to be and it will flash amber light until desired temp met. It did drop to 75.6 today but, I had the windows open over night and the room was cool. The thermometer activated until 76 was met again.. lovely job! My fish, Clark loves it and I love that it is so thin, I will add a side shot...my ONLY complaint ; is totally superficial... I wish that the lettering in front wasn't white.. it doesn't blend in much in my tank. But then my tank is smaller and it might not be glaringly obvious in a larger tank. I know this thermometer is pricey but, worth it.. I am a super worry wart and did extensive reserch on filters before choosing.. I feel completely at ease with this. UPDATE: it is now January 2018- this heater is still going strong. Works great. Just remember to unplug it for 15 mins during water changes if the thermometer is going to be exposed to air. After new water is in. Turn back on. It should stick with the previous temp setting! Highly recommend! Keeps my water at the proper set temp. Will adjust as needed on its own to keep set temp!

Terrific customer service

The customer service @ Cobalt is phenomenal! I notified them that my heater seemed to be having a problem maintaining 78 & would frequently drop to 76 & was starting to go to 74 without any changes on my part after 4 mos of use. They replaced it with a 50W as their delivery of the 25W was delayed after asking if that was OK. They were consistently kind & helpful. One of the nicest & rarest experiences I have had in several years. They like Amazon stand behind their product &/or company service. A real pleasure to do business with both companies.

Reliable Product

I purchased this the beginning of October and it still works great. It's a bit more expensive but after reading very questionable reviews by lower end products on Amazon and my local pet store competitor heaters, I decided to go out on a limb and pay the extra money for hopefully a better quality product for my betta fish. I really like the peace of mind knowing that he can't fry to death with this thing. It regulates really well; my house fluctuates so the water in his 2.5 gallon tank was sitting at 71-72 before purchasing (a little too low for a betta). Even with it being in a smaller tank, it doesn't seem to overheat and instead stays at a constant 76-77 degrees that's contingent upon my personalized setting. Based on the manual, I unplug it before I clean the tank (it says to let it sit 15 minutes) and then just plug it back in when the tank is full again. The manual also recommends to not let any plants or outside items touch the heater so I stick to this rule as well. While it is black it is pretty flat and does not get in the way of my plants, obstruct too much of my tank, and isn't that much of an eye sore. Overall, I would recommend this as a trustworthy heater for your fish and I am glad I invested in this one over the rest.

If it stopped working, here is some help

I purchased the heater on April 10, 2015 which had been working perfectly until last night (May 11, 2015) the heater stopped working. I was furious thinking that it had failed already. I e-mailed Cobalt Aquatics for help. This morning an e-mail with detailed instructions had been sent to me in response. It stated that I could unplug the heater for 30 minutes whilst leaving it in the water, and then plug it back in as sort of a "reset". I tried it and it is working perfectly again. I could not find any resolution in the Amazon Review section to my problem, so hopefully this will help someone in the future. The e-mail also detailed that if it was indeed defective, they will test and replace the item or to avoid shipping and waiting, they will offer a 50% OFF MSRP to purchase a new one. A great experience with their customer service department and a satisfied customer.

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