Can Aquarium Heater Kill Fish? (Things To Know About Fish Tank Heater)

Can Aquarium Heater Kill Fish

Can Aquarium Heaters kill fish? there is a general saying that ‘ everything that has advantages has disadvantages too, and that is why many people do wonder if a fish tank heater could kill their fish.

A heater is an electronic device that is used to maintain and control the water temperature in Fish tanks.

We all know that there are tropical fish and cold water fish, tropical fish dwells in slightly warm water with a temperature between 65 to 80°F and you need a heater to achieve that.

So, Aquarium Heater is very compulsory in every fish tank, but the question is, can it kill fish? You will find out in this article and many more.

Can Fish Tank Heater Kill Fish?

Aquarium Heater could kill fish if it malfunctions by either overheating the water or electrocuting the fish in it

Learning that it could kill your fish, you might be shaking now and making a decision not to have it in your fish tank. Well, it is not as you might be thinking.

One undeniable fact about fishkeeping is that you can’t do without a heater.

Despite the that a fish tank heater might kill your fish as a result of having faults, it is not very common for such to happen.

We all know that anything made by man could malfunction, especially when it has expired, but you don’t have to be afraid about keeping a heater in your tank because it is compulsory.

I suggest you buy a quality heater and you should be okay with it.

Can Aquarium Heater Burn Fish?

Aquarium heaters can burn fish if it malfunctions, but this rarely happens.

As I explained above, if it becomes faulty, it could overheat the water, thereby killing the fish and every living thing in it.

It could burn fish but this is not what you see every day, so relax your mind and get yourself a quality fish tank heater and you will be okay with it.

Do You Leave A Fish Tank Heater On All The Time?

An Aquarium Heater is designed to be left ON in fish tanks for 24 hours because it has an internal thermostat that automatically turns it off when the water temperature reaches the temperature it was set to maintain so that it won’t overheat the water.

This particular question of keeping a heater ON or OFF in the aquarium is a very popular question among prospective Aquarists and those who are very interested in fish keeping.

You should leave your fish tank heater ON always because it has an automatic temperature regulator.

It controls itself and you won’t have issues leaving it ON always unless it is faulty.

Will My Fish Be Okay Without A Heater For A Day?

A tropical fish could last a day or 2 without a fish tank heater and in a water temperature that is below 40°F.

The fact is, your tropical fish will not be okay without a heater for a day.

If you are talking about survival, yes they will survive, but if you are talking about being okay, I highly doubt it.

This is because all tropical fish requires a water temperature that is between 68 to 80°F and when such is not in place, they could have many health issues which could lead to their death.

Again, it depends on the nature of your fish.

If you are talking about non-tropical fish such as many species of marine fish, then they will be okay without a heater, but if it is a tropical fish, whether marine or freshwater, then it could be very risky keeping them for a day without a heater.

We all understand that your heater may break down at any time, so I usually recommend buying at least 2 Heaters and keeping one for emergency times.


Aquarium heaters could kill fish, so you should invest in a quality heater to avoid having issues with your heater and getting your fish and other animals in your tank killed.