How to Know If Your Fish Tank is Too Warm

By Eddie Waithaka @aquariawise

How Can You Tell Your Fish Tank is Too Warm

After perfectly setting up your aquarium and adding your beautiful finny buddies in there, you for sure enjoy when they are happy, healthy, and merrily swimming around in the aquarium.

Some conditions in the tank are such a big deal to ensuring that your fish have the best environment to live happily in the tank.

If an aquarist fails to satisfy these conditions, fish will get stressed and, they can even die.

Like in our case here, how can you know if your tank is too warm?

Apparently, you may not be able to see it, but your finny beauties will certainly feel it.

Fish are cold-blooded and cannot control their body temperature. They on the environment to control their metabolism and activity levels.

And keeping in mind that different fish species thrive, are happy, and healthy in an ideal range of temperatures, it’s recommendable to research the best temperatures for the fish species you want to keep in your aquarium.

Too hot or too cold temperatures will cause stress to the fish and, this is something we want to avoid in our tanks.

Since you cannot see if your tank is too warm, the only way to tell is by observing the behavior of your finny buddies in the tank.

Too warm water holds less oxygen. Therefore stressed fish due to heat will exhibit rapid gill movements, or they will move to the water surface and appear to be gasping for air.

Also, when the tank is too warm, there will be an increase in algae growth and, the water gets more dirty and cloudy.

A fish tank can only break when the temperatures are extremely high. But this is rare and, most aquarists have never experienced it.

Too warm temperatures in a fish tank affect our beautiful buddies more than the fish tanks. What about if the tank is cold?

Have you thought about it?

Well, that’s why we are here.


Follow along to have more insight and knowledge on the effects of both warm and cold air on our fish tanks.

Can a fish tank break when it’s too warm

I would say, in extremely high temperatures, it may break. But it is rare in fish tanks.

A fish tank can withstand very high temperatures.

Since temperatures in a tank rise due to either bulb, water heaters, or the environmental temperature, it’s almost impossible for a tank to heat up to a level that it breaks.

Most tropical fish thrive best at a temperature range between 24-27 degrees Celcius. Therefore if an aquarium heats up at a temperature higher than this, the fish become stressed up.

You will act to identify the cause of stress hence resolving the temperature issues before a breaking point of the tank is reached.

How Cold Can a Fish Tank Be

As we have said earlier, different fish species thrive at a range of temperatures.

Some require low temperatures while others do well at relatively warm temperatures.

We have the cold-water fish and the tropical fish.

For a cold tank, most fishes that can survive and thrive happily are the cold-water fish.

Keeping tropical fish in a cold tank will get them stressed and, they may even die.

Examples of cold-water fish kept in aquariums include the goldfish and the koi fish.

Often, these fishes grow that they may not be suitable for a fish tank.

Will Your Fish Tank Break in Cold

Many aquarists may not be sure whether it’s safe to keep their fish tanks in the cold.

There is the fear that the tank may break.

A tank kept in the cold might break.

This happens if there is water in the tank and the water freezes. The freezing water will break the tank.

It’s possible to keep a fish tank in the cold. A fishkeeper has to follow the specific restrictions for settling and adjustments while setting up the tank.

For fish tanks kept outside in the cold, you should choose cold-water fish in them since the temperature conditions will be ideal for them.

Also, fish tanks kept outside enhance the beauty of the surrounding.

How to Keep Your Fish Tank Warm in Winter

Winter is the coldest season of the year and, the amount of light during the day is at its shortest.

During this season, there are a few things that an aquarist can do to make sure that our fish keep warm and do not end up freezing to death.

One thing done by most aquarists is ensuring that they have a water heater. Ensure that the heater is working and is in good condition.

Since you cannot take it out of the water and touch it to check if it’s working, use the thermometer to find out if it’s keeping the water at a temperature that you have set.

At times, a thermometer may not help you know if the tank water is warm enough for our fish because you can not keep checking it now and then, and your heater may malfunction without you noticing until its too late

I would recommend that you have a backup heater just below the first one. Set it one or two degrees lower than the first one.

The second heater will never come on unless the first one has malfunctioned.

In case of any malfunction by the first heater, the second heater will come on automatically and, the finny buddies will not notice any change.

Also, at this season, there can be a dreaded power outage. It’s not a case of if but when. Aquarists have to be prior prepared before this happens.

You have to keep the room in which the fishes are as warm as possible.

This is made possible by limiting the traffic in and outside the room and not opening doors anyhow hence letting the cold air in.

This ensures that the room temperature is maintained therefore keeping the fish tank warm.

Another way is to cover the tank with a thick blanket but ensure that you do not completely seal it off. Ensure that there is enough air circulation in the tank.

You can also cover the tank with towels or lots of newspaper layers, therefore, ensuring that the warm temperature does not escape.

Another crucial thing is to have an emergency power supply such as a generator.

In this way, you will ensure that there is power in case of a power outage.

Have fun keeping finnies🐠🐟.

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