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Should you use a space heater instead of a dedicated fish tank heater?

If you want to heat your fish tank, the most commonly suggested way to do so is by using a dedicated aquarium heater. A lot of serious fish keepers, especially those with multiple tanks, prefer using space heaters (also known as room heaters) as a way to keep their tanks warm however. Below is a guide exploring the pros and cons of using a space heater over a fish tank heater.

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Why room heating works on aquariums

Without a heater in the tank, the water temperature will move towards whatever your room temperature currently is. Thus, if you heat your entire room, you will also be able to heat up your aquarium at the same time.

Pros of using space heaters for your tanks

Less likely to break

Based on our experience, aquarium heaters don’t really have long life spans. Rather if it is because of error on our end or because the device simple malfunctions overtime, we have to get a new one seemingly every couple of years if you are lucky. If you talk to other fish keepers, or read about them online, their experiences are also the same.

Unfortunately, it seems like the technology that power aquarium heaters won’t be evolving anytime soon in terms on having longer lasting equipment. On the other hand, most space heaters from reputable companies are less likely to break.

Won’t harm your fish

If you decide to use a heater in your aquarium, there is a chance that the protective casing may end up cracking. This could cause some big problems as the contents of the equipment may leak into the water column. It may also cause an electrical discharge throughout the aquarium as well. Both of these could be deadly to the fish you are keeping in the same tank.

Since you are keeping the space heater outside of the tank, you don’t have to worry about hurting, and potentially killing, your fish if it breaks.

Can also heat up the entire room

Another benefit of getting a space heater instead of an aquarium heater for your tank is that you will be able to raise the temperature of your entire room. Of course, it doesn’t make sense that your fish is living comfortable in warm water while you are freezing outside the glass or acrylic panels while look at them. With a space heater, you can kill two birds with one stone.

Can heat up multiple tanks

Since you are heating the room instead of a single tank, you will be able to warm up several tanks with just one space heater. On the other hand, you will need to purchase multiple fish tank heaters in order to increase the temperature for every tank you have. So, if you are planning to heat multiple tanks, then a space heater may be your best option.

Won’t take up space in your fish tank

Having an external heater will also give your fish more swimming room. Most dedicated aquarium filters are bulky and elongated. As a result, you may have to rearrange your decor, filter and/or bubbler to fit it in. Not to mention that you might want to hide it with plants and/or decor cause it could stick out like a sore thumb. If you value the space in your tank, then you should opt for a space heater.

Cons of using room heaters for aquariums

Electricity costs

One big drawback to having a space heater is the electrical costs. The most effective room heaters uses 1500W. In comparison, aquarium heaters only maxes out at 300W. If you are only planning to heat one tank, then it wouldn’t make much sense to use five times the amount of electricity to do so unless you want to keep your room warm as well.

Better insulation

Another issue with space heaters is that there are plenty of outside elements that could reduce the effectiveness of their ability to maintain the warm temperature in the room. If you haven’t insulated the walls, windows and/or doorways in your home properly, then heat will easily be able to escape the room housing your tank(s).

Although having a weakly insulated room will also make your aquarium heater less effective as well, having a top cover your fish tank will prevent heat from escaping the tank.

May need air circulation

Depending on what type of space heater you are getting, as well as how close you put the heater to your tanks, you may also need to increase the air circulation in your room. This is usually done with a fan. With that said, as long as you place your space heater close to your tank(s), then this shouldn’t end up being an issue.

Best space heater type for your fish room?

We prefer using a oil filled heater as opposed to a ceramic, electronic and other types. This is because oil heaters have better build quality and is better at heating medium to larger rooms. Not to mention that, if you have allergies, the other room heater types could cause flare ups. Last but not least, an oil heater is quiet as it doesn’t require a fan.

If you are looking for a space heater for your tank, we recommend check out the PELONIS 2019 Oil Filled Radiator Heater Luxurious Champagne Portable Space Heater with this link on Amazon.


There are many benefits of getting a space heater over a fish tank heater to raise the temperature in your aquarium. Its external nature means that it is safer for the fish, won’t take up any space in your tank, be able to heat your room and be able to heat multiple tanks.

The only real drawback to space heater is the electrical costs. With that said, the extra costs may be worth it in the long run as aquarium heaters tend to break much faster in our experience.

You may also run into issues with heat dissipating on your space heater. In that case, we recommend moving your heater as close as possible to your aquarium(s).