15 Ways to Lower Temperature in an Aquarium (With and without Equipment)

Let’s face it maintaining healthy an aquarium is tough.

And it even gets tougher in summer if you have a cold-water fish.

In this article, I am going to share with you some ways to lower the temperature in your aquarium.

What temperature should my tank have?

There is no one answer to this question. It really depends on the species of fish in your aquarium.

Generally, tropical fish can do well in the temperature of 75 to 80-degree Fahrenheit.

Coldwater fish will do well in the temperature between 60 degrees Fahrenheit to 75-degree Fahrenheit.

Depending on the fish some fish may require temperature below 70-degree Fahrenheit.

The ideal temperature for a reef tank is 75 to 78-degree Fahrenheit.

So, as you can see, the temperature for your particular aquarium really depends on the species of the fish.

So, you should do some research and find out the ideal temperature for your fish and then you should adjust the temperature of your aquarium accordingly.

Know the maximum and minimum temperature range for your particular aquarium

Before we dive into the ways to lower the temperature of your aquarium, you should know what is the maximum and minimum temperature range for your aquarium.

You can know this range by researching what is the ideal temperature range for the fish in your aquarium.

Also, while reducing the temperature of your aquarium you should regularly monitor the temperature of your tank using a thermometer.

Check out our recommended Thermometer

Ways to Lower the Temperature in Your Aquarium

1.Remove the lid

As soon as you notice the high temperature in your aquarium you should immediately remove the lid of your aquarium.

The thing is, there is continuous water exchange going on the surface of your aquarium.

And if you have covered your aquarium with the lid then the heat will get trapped and it will go again into the aquarium that will ultimately raise the temperature of your aquarium.

So, removing the lid from the aquarium will help to lower the temperature of your aquarium

2. Turn Off the Lights

You can check if your light is producing heat or not by simply moving your hand just below the lights.

If you feel any warmth then your light is producing heat which is responsible for raising the temperature in your aquarium.

So, in this case, you should switch off the lights of your aquarium.

If you have a planted aquarium then obviously you cannot switch off the light of your aquarium permanently.

So, in this case, you have a couple of options.

You should first do the research on how much minimum light does the plants in your aquarium require.

Once you know that then you should turn on the lights for minimum hours.

If your aquarium lights come with a functionality that allows you to lower the light then you should use it.

This way you can keep the lights of your aquarium for more time at low intensity and it will not contribute to the rising of the temperature of your aquarium.

Another thing you can do is simply put a couple of blocks on both ends of your aquarium and keep the lights on it.

There should be some space between your lighting and the surface of your aquarium so that the heat trapped between the light and the surface of the aquarium will have a way to escape.

You can also put a table fan beside your aquarium in such a way that the air will blow along the surface of your aquarium.

This will immediately blow away the hot air between the light and the surface of the aquarium.

3. Keep a table fan near the aquarium

There is constant heat exchange going on on the surface of your aquarium.

So you can blow away the heat located on the surface of your aquarium by using table fan.

You should put a table fan near your aquarium in such a way that the air coming from the table fan will blow away the heat on the surface of the aquarium.

But before doing this just be sure to remove the lid of your aquarium.

4. Use a cooling fan

A convenient way of blowing the air located above the surface of your aquarium is by using a cooling fan specially designed for aquariums.

I have already mentioned about the DIY alternative of the cooling fan.

The cooling fan will just make it convenient.

5. Put ice cubes in your aquarium

The instant way to cool down the temperature in your aquarium is by using ice cubes.

Just put some ice cubes in a zip-closed bag and hang it inside your aquarium.

The ice will slowly melt and it will cool down your aquarium.

But you should be very careful while using this trick.

Because it can cool down your aquarium very rapidly.

And if you lower the water temperature more than 2-3 degrees Fahrenheit within 4 hours then it can shock your fish.

So, you should constantly track the temperature of your aquarium while using this trick using a thermometer.

6. Put a frozen water bottle on the aquarium

This trick works the same way as putting ice cubes into your aquarium.

But I think it is safer than putting ice cubes directly into your aquarium.

Just make sure that you are using the bottle according to the size of your aquarium.

For example, if you what to cool down a small 10-gallon tank then you should use 200 to 300 ml bottle for it.

If you have a large tank then you can go for a large 1-liter bottle.

Again, while using this trick you should be careful that you are not lowing the temperature of the water more than two to three degrees within 4 hours because it can shock your fish.

So, you should constantly track the temperature of your aquarium using a thermometer.

7. Move your aquarium

The mistake most beginners make is that they choose the wrong place for their aquarium.

If your aquarium is in the room where there is a lot of sunlight or if your aquarium is directly exposed to the sunlight then you should move it to another room where there is no sunlight.

Sunlight can cause a rise in the temperature of your aquarium.

You should be also careful that you are moving your aquarium in the room where there is good ventilation.

If you can move your aquarium in the room where there is good air conditioning then it will really help to lower the water temperature of your aquarium.

Also, the temperature will not drop down suddenly so there will be no risk of shocking the fish.

You should also make sure that there are no heating vents or fireplaces nearby your aquarium.

Because that can also raise the temperature in your aquarium.

8. Turn down your heater

First of all, you should make sure that your heater is calibrated with the temperature you want in your aquarium.

If the temperature of your aquarium is still very high then you should turn down your heater.

Here you should note that you should not switch off or unplug your heater.

Because it can cause a sudden drop in the water temperature of your aquarium that can shock your fish.

Besides, it can also cause other complications like it can cause itch in your fish or they may get affected by other parasites.

9. Partial water change

This is a very easy way to lower the temperature of your aquarium.

You can do a partial water change of about 30 to 50% of your aquarium water.

When you introduce the freshwater in your aquarium make sure that its temperature is slightly lower than the temperature of your aquarium water.

Here you should be careful and you should not add very cool water in your aquarium.

Because it will suddenly drop the temperature of the whole aquarium and it can shock your fish.

10. Keep the room cool

Keeping the room cool where you are aquarium is placed in a great way to lower the temperature of your aquarium.

So you should put your aquarium in the room where there is good airconditioning.

When you lower the temperature of your aquarium using this method there is no risk that the temperature of your aquarium will lower suddenly. So it will not shock your fish.

11. Increase surface agitation

Surface agitation plays a big part when it comes to lowering the temperature of your aquarium.

Surface agitation is the place where heat and gas exchange happens.

So if you increase surface agitation it will help to lower the temperature of your aquarium.

There are several ways to increase surface agitation

• You can install an air pump to increase surface agitation. The bubbles coming out from the air stone will move towards the surface of your aquarium and it will help to increase surface agitation. Check out our recommended Air Pump
• You can install a hang on the back filter or you can use a spray bar to increase the surface agitation.

Besides lowering the water temperature, there are several other benefits of surface agitation.

Benefits of surface vegetation

• Surface agitation helps to oxygenate the aquarium.
• Surface agitation is also necessary for beneficial bacteria.
• Surface agitation also helps to maintain the pH of the water.

12. Install drip system

Installing a drip system is also a very good way to lower the temperature of your aquarium.

The good part about this method is that it will not cause a sudden drop in the water temperature of your aquarium so it will not shock your fish.

Also, when you install a drip system you will no longer have to do a partial water change.

13. Replace the faulty equipment

Sometimes it is the faulty equipment that can cause a rise in the temperature of your aquarium water.

So you should check if your heater is working properly or not.

You should also check if your heater is calibrated or not for the temperature you want in your aquarium.

If you are using a canister filter with UV light functionality then sometimes that UV light can get so hot that it can raise the temperature of the water.

So, in this case, you can turn off the UV light and use it for a couple of hours every day.

14. Keep Live Plants in Aquarium

Keeping live plants also help to keep the temperature low in the aquarium.

When the plants are grown to the surface of the aquarium, it will prevent the light coming into the aquarium.

You can also keep floating plants to prevent the light coming tinto the aquarium.

That will prevent the rise in the temperature of the aquarium due to the heat of the light.

Besides keeping the temperature low, live plants have many other benefits.

I have written about all of them in this article.

15. Use aquarium chiller

This is probably the most convenient way to lower the temperature of your aquarium.

What is an aquarium chiller?

An aquarium chiller is nothing but a kind of refrigerator. If you know how the canister filter works then the aquarium chiller basically works the same way.

It sucks the water into its compartment, cools it down and then sends the cool water back into the aquarium.

Do I really need an aquarium chiller?

Aquarium chiller is more common in the reef tanks because reef invertebrates require a very stable water temperature and they cannot survive in high water temperature.

Usually, tropical fish can survive in warm water for a couple of weeks but marine fish cannot survive in warm water that’s why aquarium chiller is very common in reef aquariums.

If you have cold-water fish like Goldfish then it is a good idea to get an aquarium chiller depending on the size of the aquarium.

For example, if you have a very big tank then it will be very convenient if you just use an aquarium chiller to lower the temperature of the water.

Overall, it is not a must-have but it just makes lowering the water temperature very easy if you have a large tank.

How to maintain a low temperature in an aquarium.

So now that you know the several ways to lower the temperature of your aquarium, it is very important to maintain the low temperature for a long time, so that you can get the most out of the efforts you put in to lower the temperature of your aquarium.

1.Insulate your tank

You can insulate your tank using foam to maintain a low temperature in your aquarium.

Just wrap the foam around your aquarium and be sure to keep the upper part i.e. the surface of your aquarium open.

Now I know, by doing this you will not be able to see your aquarium. 

But you can isolate your tank when you are away from your home i.e. when you are on your job and nobody’s home.

And when you come back home then you can remove the insulation so that you can see the tank and your fish.

2. Aquarium temperature controller

You can use a temperature controller to maintain the ideal temperature for the aquarium.

Basically, you have to connect your heater with the temperature controller.

Then you have the option to set the maximum and the minimum temperature for your aquarium on the aquarium temperature controller.

As the heater of your aquarium is connected to the temperature controller, when the temperature reaches the highest mark, the temperature controller will shut down the heater automatically.

And will automatically turn it on when the temperature gets on the ideal range.

The temperature controller will also notify you when the temperature of your aquarium gets too low.

Conclusion

I hope you will found these ways to lower the temperature in your aquarium helpful.

Temperature is a very important component when it comes to maintaining a healthy aquarium. So you should regularly track the temperature in your aquarium and use the above ways to reduce it.

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