Can an Aquarium Heater Burn a Fish?

When I installed my heater it came with a protector, and I wondered if the protector was there to protect the fish or to protect the heater. This sparked my interest and I quickly went online to research. This is what I found.

Is it possible that an aquarium heater can burn a fish? Although not likely, this is possible. It only happens when a fish gets stuck between the aquarium glass and the heater. The main risk for heater burn wounds are secondary infections.

Although quite rare, you want to take measures to prevent your fish getting burned by your aquarium heater. Although your fish may act like nothing happened, it is super unpleasant for them. Here is additional information regarding this topic.

How to Spot if Your Fish Got Burned

If your fish got stuck and got burned by the heater, its instinct will tell him to continue to act normal. This is because acting different will attract predators. This makes it harder for us to see if something is wrong with our fish.

But we can spot a burn mark on the skin of our fish.

Initially the burn mark on the fish will not look too bad. The skin will look a bit white/pale and the gills will look more transparent. If the fish has been burned rather bad the wound will look worse after a couple of days.

First Aid for Fish That Got Burned

If you notice that one of your fish got burned, you will have to take a couple of steps. First of all you have to assess the severity of the wound. If it is super serious, your fish might not make it. You should take the following precautions.

The most important part in taking care of a burn mark of your fish is preventing further infections. A wound like the one your fish is suffering from is prone to other infections, as the immune systems and the mucus layer that usually protect the fish has been damaged.

To do this, you should keep up on your water changes. I would recommend doing a daily 20% water change for a while until the wound on the fish seems to heal. Doing these additional water changes will keep the ammonia, nitrite and especially nitrate concentrations low.

Another thing you can do is to add salt to your aquarium to reduce the osmotic pressure. A good dosage of salt to reduce the fish’s stress is around 1 tablespoon (3 teaspoons) for every 5 gallons (19 liters). Do not go overboard with the salt, and when you use salt you can either use regular kitchen salt without additives or dedicated aquarium salt.

Tip: If you have another smaller tank available, use that for the salt treatment. If not, you can treat the main tank but that takes more salt.

Prevent Your Heater From Burning Your Fish

A fish getting burned by a heater might be very rare, but that does not make it less problematic. If you are worried about this happening to your fish you can take precautions by covering your aquarium heater in a plastic protector.

This is the first and major way to protect your fish against these burn marks. These plastic heater protectors are not that expensive. You can check the latest price on an amazon listing here. Do make sure that the protector is compatible with your heater.

Other Questions

Can an aquarium heater touch the gravel? It is best that your aquarium heater does not touch either the gravel or the glass, because it can create a temperate gradient on the glass. This can create tension on the class which might cause it to shatter.

Feature image reference: Link under CC3.0

Bart Sprenkels

I have been keeping multiple aquariums since I was 18 years old. Just like many of you, I started with two goldfish but quickly learned they were not suitable for aquariums. Later, I switched to a tropical community tank and I also have two pet musk-turtles in a bigger aquarium. You can read more about me here.

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