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Aquarium Heaters Buyer’s Guide

Getting the right heater for your tank is a challenging task. If your water doesn’t feature the appropriate temperature, your fish will probably won’t survive. Also, if the heater does not answer specific requirements, you are likely to spend more money on new fish or in vain heaters purchases.

After tons of research and years of failing in getting a balanced temperature, I finally found the Cobalt Aquatics Neo-Therm Pro Heater (link to Amazon). That was the only heater that kept my water steady enough to grow my most delicate fish. The reason I haven’t bought it in the first place was the above-average price. However, I ended up spending much more on alternative tank heaters, which were awful. I also had to spend money frequently on fish that didn’t survive.

The most important takeaway from this product is that you should get a heater which doesn’t make the temperature fluctuate. It could be that the average temperature during the day is steady, although it tends to jump up and down with broad gaps. After testing the Cobalt Aquatics and comparing it to others, there is no doubt it brought the best results.

Here is a table I’ve made to help you pick the precise model according to your tank dimensions. The only thing that changes is the watts:

Tank SizeWatts
Up to 6 gallons25W
Up to 12 gallons50W
Up to 20 gallons75W
Up to 29 gallons100W
Up to 40 gallons150W
Up to 55 gallons200W

The Cobalt Aquatics’ Advantages

There are so many tank heaters out there that choosing the right one seems impossible. Frankly, it got me frustrated quite frequently. I ended up thinking there is no way to figure which one is the best without buying and testing myself. Nevertheless, there are a few things you should know up-front.

Narrow Temperature Swings

Those of you who have grown fish for years, know that the number written on the heater doesn’t always reflect the actual water temperature. In many cases, it is the average temperature during certain times.

For example, if you set the thermostat to 78 degrees, it could be 79 or 77 for a while, although the average is still 78. The problem is that the fish rarely get the precise temperature you desire. Also, some fish will respond negatively to fluctuations. Frankly, I believe that this is one of the reasons my fish haven’t grown successfully in the past.

To make it more visual, I made a comparison chart. I recorded the temperatures I received with my previous heater, the Tetra HT Submersible Aquarium Heater (link to Amazon).

To test whether or not the Cobalt Aquatic is indeed better, I checked the water temperature every hour for an entire day. I’ve used two identical tanks with no fish and submersed the two heaters accordingly.

As you can see, the results favor the Cobalt Aquatics Neo-Therm Pro Heater, since the temperature tends to be much more stable. When I set it to 78, it never went above 78.5 or below 77.5. However, the Tetra HT featured much higher swings. 

Still, back in the days, it was much cheaper. That is why I bought it in the first place. However, I ended up purchasing excessive heaters which were a total waste.

The bottom line – go with the Cobalt Aquatics for a static temperature range. It will probably result in healthier fish. Even though it costs more, it will save you money down the road.  

Such an Aesthetic Design

Adding a heater to your aquarium many times interrupts with your current design. Personally, I like decorating my tank as much as possible. It is an integral part of my hobby.

One of the things I liked about the Cobalt Aquatics Neo-Therm Pro Heater is its flat shape. It doesn’t have this cylindrical design, which doesn’t get along with anything. Instead, it is attached to the back of the tank and can be hardly seen (especially if you blackout the background with a dark sheet).

What I also like about the design is that the vacuumed rubbers stay attached to the walls once you take the heater out. When you put it back, you merely slide it inside. This way, you don’t put any effort or make startling movements to your fish.

Easy Temperature Adjustments

One of the things I hated about previous heaters was that I had to set the temperature by spinning a knob at the top. This is just a terrible experience. You can never know the precise temperature you’ve set. Instead, you see red lines that are too thick to point the numbers. 

This is not the case with the Cobalt Aquatics – its temperature adjustments is one of the simplest I’ve encountered. Merely set the green light to the desired temperature.

You will immediately see an orange light appears (this one measures the current temperature). As time passes, you’ll see it climbs up toward the green light. Simple as that. Just set it and leave it.

Will The Cobalt Aquatics Work With Large Tanks?

Personally, I own the Tetra 20 Gallon Complete Aquarium Kit (see my review), and it works great. However, some of you might have larger tanks, 55 gallons, for example.

Well, I cannot tell from experience, so I went researching online. According to some comments I’ve seen, people had a great experience with it in their 50 gallons tank.

However, keep in mind that you might need a model with higher watts (it might be a bit more expensive). According to the manufacturer, the 200W model should work just fine with tanks up to 55 gallons.  

How About Relatively Small Tanks?

Some of you might worry that the Cobalt Aquatics is too large for the aquarium. From the comments I’ve read online, people had good experience with it while raising their bettas in a 3-gallon tank.

The only takeaway was that you should ensure upfront that the heater will be submerged entirely inside the water. Measure the length or height of your aquarium (depending on how you place it), and make sure the heater isn’t too long.

The smallest one (25W) is 3.2 x 2.2 x 7.8 inches. Regarding water temperature – it won’t get too hot due to a smaller tank. Once the temperature reaches the desired range, the thermostat will shut the heater off. 

Featured Image: Flickr