Safety Features - integrated thermal protection circuitry shuts the heater down before it can overheat. Outer casing is shatterproof making the NEO-therms virtually indestructible. Use for freshwater and saltwater aquariums and terrariums.
Correct heater position- Vertical with heating element down, bezel, cord and button up.
- Minimum water level - Top of the bezel.
- For 25, 50, 75 Watt - 5.5" from bottom of the heater
- For 100 Watt - 8.75" from bottom of the heater
- Maximum depth of 31.5" deep at the bezel
Quick Compare - Cobalt Neo-Therm Submersible Aquarium Heaters
|Model No.||Maximum Aquarium Size||Dimensions|
|25W||6 Gallons||6 1/2" L x 2 1/8" W x 4/5" Thick at Bezel|
|50W||12 Gallons||6 1/2" L x 2 1/8" W x 4/5" Thick at Bezel|
|75W||20 Gallons||6 1/2" L x 2 1/8" W x 4/5" Thick at Bezel|
|100W||29 Gallons||9 3/4" x 2 1/8" x 4/5" Thick at Bezel|
|150W||40 Gallons||10 7/8" x 2 1/8" x 4/5" Thick at Bezel|
|300W||75 Gallons||10 7/8" x 2 1/8" x 4/5" Thick at Bezel|
Note: 300W model consists of two connected heating elements that measure 10 7/8" x 2 1/8" x 4/5" each.
Too much $$ for a premature failure By Reefer Reborn on 11/2/2017Reefer Reborn wouldn't recommend this product to a friendYou will be extremely impressed with the product keeping the temperature within a half degree day in and day out until suddenly it stops working after 2 months. My unit was blinking current temp slow Yellow LED and Target Temp solid Green LED but was not connected to the heating element. It could have been worse and got stuck on in the heating mode (Negative Star review for sure) but thank God Cobalt has a system to prevent that. The friendly staff a Cobalt are sending a new one and I guess I will try it once more because I love the =/-.5 degree so much. If doing it all over I would just by a classic heater and or one of the fancier ones and an external controller. perhaps when I get my corals in I will buy a 77.5 degree Walmart one to back this one up so the drop is not 5 degrees over night from 78/79 my target temp.
I've loved these heaters so far, but I'm going to remove them anyway By Randall on 10/2/2017Randall would recommend this product to a friendLooking at the other reviews, it seems that a fair number of people have significant issues with this heater. That is unfortunate because the design is fantastic; this thing is almost impossible to physically damage accidentally. And the temperature regulation by the internal thermostat is top-notch, possibly the tightest control available in a heater-thermostat combo.
I am running two 200W NeoTherms in tandem, with the internal thermostats set to 80 degrees F, but actually controlled below that level by an Apex and it's temp probe. In order for overheating to occur, both one of the heaters and the Apex would have to fail at the same time; not likely. For underheating to occur, both heaters would have to fail. Again, not likely. With this setup, I can easily maintain my tank temp within 0.5 degrees F, day and night.
It doesn't take much searching to discover that these heaters have caused some people utter disasters. Starting around 2014, people would find that the 200W version, in particular, would crack open, spewing out crud into your water, and smoke and vaporized epoxy into the air, killing virtually everything in the tank and almost impossible to completely clean out afterwards. Complete disaster.
This problem was mostly seen with the 200W version (which you'll notice BRS no longer carries, although it's still produced). Cobalt claimed to have re-designed the heater by 2015 and the online complaints largely subsided. Problem fixed? Well maybe not. I just saw a recent post about a 150W version with confirmed production date 8/16 that did this - huge crack down the length of the heater, crud all over it, sump trashed, dead tank, house smelling like burnt plastic.
So, NOPE, can't have it, even if the risk of it happening is a small one, it's too much considering the magnitude of the disaster if the case on one of these heaters cracks. Glad I came here to do this review, otherwise I might not have known until it was too late. Going to buy a couple of Eheim Jaggers now.
Works great for me By Kenae on 8/23/2017Kenae would recommend this product to a friendNo real issues, read a few complaints on this heat but I have yet to have any of these issues. All in all it works great. Goes about 1/2 a degree higher than I set but it's good.
Shocked By Kecked on 6/30/2017Kecked wouldn't recommend this product to a friend150w heater failed and shocked me. No idea why. Killed some coral too
Accurate but dumb By Blake on 5/9/2017Blake wouldn't recommend this product to a friendSo... if you're looking for accuracy, then you'd be hard pressed to find a better heater. However, my 300w heater requires two linked units, dumb, it also uses the loudest switch this side of the Mississippi to turn on and off (per unit!), dumb, it leaches so much voltage that my Neptune apex jumps a full number (34.5-35.5) of conductivity when it switches, dumb!
I love this heater By Robert on 5/3/2017Robert would recommend this product to a friendI have 3 of them all different sizes in different size tanks I haven't had any problems everybody is talking shit about the 200 watt. I cant even find a 200 watt in the neotherm model I don't know what they are talking about
No issues (YET) By Randall on 4/15/2017Randall would recommend this product to a friendBeen running for a few weeks now and so far all is OK.
Heater Stuck on High By Patrick on 3/15/2017Patrick wouldn't recommend this product to a friendYesterday I had a very brief power outage. Later on that evening I noticed my Neo-Therm had the most right Red LED was lit. Also the tanks temperature was at 94 degrees. I immediately unplugged the heater and used a backup. I believe I was lucky based on the forums and reviews I’m seeing on line many have not caught it in time and had much more disastrous results. I have another 100 watt from them but I’m not going to use it. It’s too bad because the features, slim design and appealing look are a great selling point. But it’s not worth the risk after seeing the stories of the heaters blowing up, cracking, shocking people and burning up I can’t take the chance. One of the selling features I was sold on was that it less likely to fail in the on position. From the amount of instances online apparently that’s not true.
150w By willy on 1/11/2017willy would recommend this product to a friend150watt working great no issues
works great By Ruben on 1/11/2016Ruben would recommend this product to a friendthe fact that i can get this in my ac70 refugium and not in my display makes it worth it plus haven't had any issues with it
Great By Derek on 8/10/2015Derek would recommend this product to a friendabsolutely, love how low profile this heater his and thus far it has been very accurate and is very responsive with my Neptune Apex.
Great Heater By Katherine on 5/15/2015Katherine would recommend this product to a friendI have now had this heater for a year in my 29 gallon Nano. The temperature has NEVER deviated from the setting. Need I say more? I am very pleased.
Ask a question
Is the 25Watt Neo-Therm ok for me to use in my tank?
I would like to set it about 78 and hold it there.
My last heater rose the water to almost 88. Not good.
Typically 2.5-5 watts per gallon are recommended. While the 25 watt could work if left on the lowest setting and certainly can work well with safety built in it has the potential to over heat if left on too warm of a setting.
What kind of cobalt heater do I need, how many watts
You will want 2 of the 200 watt heaters for good coverage of your tank! Feel free to let us know if you have any further questions!
Have a great day!
We expect around 1.6 amps. Feel free to let us know if you have any further questions!
It won't shut itself off (I don't know of any heater that would). You will want to unplug it before its removed from water (or if you have an aquarium controller you setup something like a feed mode to shut down your pumps, heaters, etc at the press of a button for when you do a water change).
There isn't a calculator as each heater is a bit different, but all of the manufacturers do have recomended size aquariums for their heaters. If you look at the full details of this page there is a quick comparison chart to help you match the heater size to how big your aquarium is.
Thats not a problem at all. If the heater is larger it just won't run for as long, nothing to worry about!
Most of us around here use the Neo-therm but the second most popular has to be the finnex HMO series heaters. Assuming you don't have an aquarium controller yet I would get something that has a digital thermostat as they are a lot less likely to fail (in particular in the ON position).
I think they should be here this week :-) The different outlets have different amperage allotments but in general unless you are using two very large heaters your not going to run into any issues :-) Just for example, the 8amp outlet would be able to power about a total of 950watts. Should be way more then plenty for a 55g tank!
The heater should remember the tem, but that said with a setup like this what you would want to do is set your heater for your desired temp (say 78 degrees) and then set your Apex as an emergency cutoff to cut the power if the temp gets too hot and it appears the heater has failed (say 79.5 degrees). That way the heater is in primary control and you will avoid constantly cutting power to and from it (which may be hard on the heater).