How to Cool Down an Aquariums Water Temperature

How to Cool Down an Aquariums Water Temperature

The temperature in an aquarium can rise to dangerous levels especially if you live in an area with very hot summers. This can cause harm to your fish, and it can even stress plants and corals. In order to deal with this, you need to know how to cool down an aquariums water temperature before it causes any problems. In the following article, we will go over everything you need to know to cool down your aquarium, and also what equipment you can use to keep your water temperature stable.


Best Aquarium Chillers


JBJ Aquarium Arctica Titanium Chiller

IceProbe Thermoelectric Aquarium Chiller

Hydrofarm Active Aqua Chiller

Hamilton Technology Aqua Euro Max Aquarium Chiller

Zoo Med Aqua Cool Aquarium Cooling Fan

IceProbe Thermoelectric Aquarium Chiller




How to Cool Down an Aquariums Water Temperature

How to Cool Down Aquarium Water Temperature - Freshwater Goldfish

There are a number of ways to keep an aquarium cool when the temperature starts rising. Some of the methods to control an aquariums water temperature can be simple and inexpensive, while others can be a little more involved and costly.

If your aquarium’s water temperature is just slightly elevated then there are some easy things you can do to bring down the temperature. If, on the other hand, your aquarium’s water temperature is significantly above normal you might need to invest in a more powerful cooling system.



Aquarium Cooling Fan (Click to Buy Online)

Using a fan to blow air across the surface of the water can be one of the easiest ways to cool down an aquarium. This technique takes advantage of evaporative cooling to help remove any excess heat from the water.

The air blowing over the water will cause it to experience a phase change from liquid to gas. This phase change causes the water to release energy in the form of heat, which in turn will help lower the temperature in your aquarium.

Using a fan to cool down an aquarium does have some limitations you need to take into consideration. A fan will only be able to lower the water temperature by a few degrees in most situations. In addition, evaporative cooling won’t work as well if you live in a humid climate.

If the humidity in your house is above 50% to 60% then a fan might not be that effective. In that case, you might want to consider running an air conditioner or purchasing a chiller (Buy Online) for your aquarium.


Air Conditioner

Frigidaire 8,000 BTU (Click to Buy Online)

Running an air conditioner can keep your aquarium cool, while also having the added benefit of keeping you comfortable in sweltering temperatures. An air conditioner will lower the ambient temperature in a room by up to 10 to 15 degrees Fahrenheit if you have an efficient unit.

In most cases, a fish tank will reach thermal equilibrium with its environment as long as there are no other heat sources in or around the aquarium.

If you’re looking for ways to cool down your aquarium’s water temperature you might not already have an air conditioner. They can have a high upfront cost, and they will run up your electric bills in the summer. However, they will at least keep both you and your aquarium cool, which is more than you can say for an aquarium water chiller.

In the long run, buying a small air conditioning unit is the best choice if your house is very hot, and you want a simple and easy way to control your aquarium’s water temperature.



JBJ Aquarium Arctica Titanium Chiller (Click to Buy Online)

An aquarium chiller is a specialized refrigeration unit that is designed specifically to lower an aquariums water temperature. These units are mostly used on larger aquariums, and they can handle significant overheating problems.

There are two types of chillers that can be used to lower an aquariums water temperature. The first type uses the thermoelectric effect to lower the water temperature. While the second type uses a large heat pump that is powered by a compressor to move the excess heat out of the aquarium.

Thermoelectric chillers tend to work best on small to mid-sized aquariums. They also run silently since they don’t use any moving parts to cool down the water. You can get thermoelectric chillers that are totally passive which have a cooling probe that you can directly insert into the water, or there are also thermoelectric chillers that can be connected to a circulation pump so they can be mounted anywhere outside your aquarium.

Aquarium chillers that use a compressor are very similar to an air conditioner or a refrigerator. These types of chillers can handle almost any size tank, and they are even used to keep aquariums cool outside in very hot temperatures.

Compressor based chillers can use a lot of electricity, and most of them vent their heat back into the room they are housed in. That’s why it can actually be counterproductive to use one unless you keep it in a separate room in your house, or if you vent the heat outside so it doesn’t end up back in your fish tank.



Ice can be a quick and easy solution if your aquarium’s temperature has reached dangerous levels. If you need to reduce your aquarium’s water temperature fast, you can get some ice cubes out of the freezer and put them in a plastic bag. Then float the bag of ice on the surface of the water. The ice will start to melt which will quickly remove the excess heat from your aquarium.

You can also use water bottles filled with frozen water since they are easier to handle, and they have the added benefit of being reusable. You will have to make sure that you have enough frozen bottles on hand so they are ready at a moments notice. If you find that you are relying on ice cubes or frozen water bottles on a regular basis, you might want to consider a more permanent solution like a fan or a chiller.

You also have to be careful when you use ice to cool your aquarium since it can actually cause the temperature to drop below a safe level, which can cause harm to your tanks inhabitants. That’s why this technique should only be used in emergencies, and you should keep a watchful eye on the temperature at all times, and make sure to remove the ice once the tank reaches the proper temperature.



Blackout Curtain Set (Click to Buy Online)

Excessive artificial and natural light can cause the temperature in your aquarium to rise in certain situations. Some light bulbs can emit a good portion of their light in the infrared spectrum. This infrared light is then absorbed by the water which can elevate the tanks temperature. If you want to avoid this problem you can use a LED light (Buy Online) since they emit far less infrared radiation.

Your lights ballast or power supply can also be a source of heat that can lead to water temperature problems. Even LED and fluorescent lights have ballasts and power supplies that give off heat during normal operations. One good solution to deal with this heat coming from the fixture is to either run the light for a shorter period of time, or you can elevate the fixture above the tank so the heat doesn’t find its way into the water.

Reducing the amount of sunlight in a room can also help control an aquariums water temperature. Most people know that sunlight can cause algae problems, but very few people consider how much sunlight can affect an aquariums water temperature.

The energy density of sunlight at sea level is around 1,000 watts per square meter. That means if you let just one square meter of light into your room it’s almost the same as running a small space heater. You can limit the amount of sunlight that enters a room by using blackout curtains (Buy Online). You also want to keep your aquarium in a room that isn’t on the south or west side of the house since those rooms tend to be warmer due to the fact that they get more sun exposure.




Aquarium Chiller Reviews



IceProbe Thermoelectric Aquarium Chiller

The IceProbe Thermoelectric Aquarium Chiller (Buy Online) is one of the most popular DIY thermoelectric chillers for small to medium sized aquariums. This chiller can reduce the temperature in a 10-gallon tank by 6 to 7 degrees Fahrenheit, or it can cool down a 40-gallon tank up to 2 degrees Fahrenheit. If you use two of these chillers together you can expect to double the temperature reduction.

The one thing this thermoelectric chiller doesn’t come with is an integrated temperature controller. This unit will run 24/7 unless you purchase a separate temperature controller (Buy Online). Once you connect this unit to a controller it will turn on and off automatically, and it will keep the water in the aquarium at whatever temperature you set on the controller.




JBJ Aquarium Arctica Titanium Chiller

The JBJ Aquarium Arctica Titanium Chiller (Buy Online) is one of the best aquarium chillers, and it is built with the highest quality materials and craftsmanship. This line of chillers is powerful enough to cool down aquariums that range in size from 40 to 340 gallons.

The thing we really like about the JBJ Aquarium Arctica Titanium Chiller is that it is easy to install, and it doesn’t take up a lot of space, so it can easily be tucked into an out of the way area. You can also connect it to hoses that have either a 1/2”, 5/8”, or 3/4” diameter, which means you won’t need to change up your plumbing to connect this unit to your aquarium.

The heat exchanger in the JBJ Aquarium Arctica is one of the best since it is made of titanium. You won’t find this expensive metal used in lower quality chillers, but JBJ incorporated it into their chillers since it has a much higher thermal conductivity. That means this chiller will be able to cool down an aquarium faster, and it will use less energy in the process.

Making temperature adjustments is a simple task thanks to the large easy to read LED panel on the front of the unit. It also has a smart memory feature that will remember your last temperature setting in the event of a power outage.

The JBJ Aquarium Arctica Titanium Chiller is also very quiet since it has vibration dampening material incorporated into the housing. It also comes with a 2-year warranty, which is the best warranty you can get for any aquarium chiller.




Hydrofarm Active Aqua Chiller

The Hydrofarm Active Aqua Chiller (Buy Online) is a very effective chiller that can be used in a number of applications. This chiller comes in three different sizes that can cool down aquariums that range from 20 to 250 gallons.

The Hydrofarm Active Aqua Chiller comes with two sets of fittings so it can be connected to either 3/4” or 1/2” inch tubing. It also has a built-in thermostat that can be set using the two buttons on either side of the large LED control panel. The temperature controller also has a memory feature that will remember its last temperature setting if the power gets cut off for any reason.

This chiller is also environmentally friendly since it uses R134a as its coolant instead of freon. The Hydrofarm Active Aqua Chiller is extremely effective at cooling water since it can also be used outdoors to cool hydroponic systems. That means this system can keep water cool outside even if the water is exposed to direct sunlight all day long for many hours.




Chill Solutions Thermoelectric Aquarium Chiller

The Chill Solutions Thermoelectric Aquarium Chiller (Buy Online) is the best all-around thermoelectric chiller for small to medium sized aquariums. This chiller can reduce the temperature in a 10-gallon tank by 10 degrees Fahrenheit. If you use it in a larger 30 or 40-gallon tank you can expect to see a temperature reduction of 2 to 4 degrees Fahrenheit.

The best thing about this chiller is that it has a built-in digital thermostat that can be set via the large easy to read LED control panel. This thermoelectric chiller will need to be connected to your circulation pump. It should be simple to install if you are currently using an external filter since all you will need to do is connect it to your existing plumbing. If, on the other hand, you are currently using a submersible in-tank filter or a hang on the back unit this chiller might not be the best option.

If you don’t use a circulation pump with external plumbing then the IceProbe Thermoelectric Aquarium Chiller is a good alternative if you still want to get a thermoelectric chiller, but it will require a little more work to install and configure.




Aquarium Cooling Fans



Zoo Med Aqua Cool Aquarium Cooling Fan

The Zoo Med Aqua Cool Aquarium Cooling Fan (Buy Online) is a well-designed fan that will help cool down the water in your aquarium. This low profile fan can be mounted on the side of almost any fish tank using the built-in suction cup. It also hooks over the rim of the tank, so it won’t fall into the water even if the suction cup detaches for any reason.

The Zoo Med Aqua Cool Aquarium Cooling Fan runs on 12-volt power, so it is much safer to use around water than most fans that use higher voltages. This fan also has an adjustable air flow nozzle, which will allow you to adjust the airflow to hit the water at almost any angle. Overall this is one of the best fans you can get to cool down an aquarium since it has one of the best form factors, and it is safer than mounting a standard 120-volt fan over your aquarium.




IPETTIE Aquarium Cooling System Fan Chiller

The IPETTIE Aquarium Cooling System Fan Chiller (Buy Online) is a versatile fan that you can use to cool down the water in your aquarium, or you can even use it as a cooling fan to keep your lights from overheating. You can get this cooling system with 2 built-in fans if you have a small fish tank, or you can get one with up to 6 fans if you have a larger aquarium.

This fan is easy to attach to almost any aquarium since it has mounting brackets that can adjust to fit tanks with walls that are as thick as 15 mm. This fan also runs on 12 Volt power, which makes it much safer to use around water. It also won’t use much electricity since the small 2 fan unit uses only 3 watts of power, and the large 6 fan model only uses 9 watts of power.

In a best-case scenario, this fan system can cool down a small aquarium by 2 degrees Fahrenheit in about 24 hours. Of course, this will vary depending on humidity and the ambient room temperature. You could also use this fan unit to cool down your lights, which will help them last longer, and keeping your lights cool can also help reduce your aquariums water temperature.

Mark Young
Mark has worked with a wide range animals for over 10 years, and he regularly volunteers at his local animal shelter. Mark has decided to share his years of knowledge by writing helpful guides for both new and experienced pet owners