Aquariums need to be maintained at temperatures that are optimal for the species that you are keeping. If the temperature gets too hot, it causes the aquatic animals stress and they will not thrive. Fluctuations of temperature can be caused by climate, heating and by devices associated with aquariums including lights and filtration pumps.
You can control these fluctuations and keep your aquarium at a nice cool operating temperature by installing an aquarium chiller. Some are simply fans that clip to the top of the aquarium but others are mini-refrigeration units that cool the water. They can be fitted in-line or can be drop-in and you can set the required temperature. To help you make the right choice, check out our guide to the best aquarium chiller.
Perfect for use with an aquarium, this quarter HP chiller will maintain just the right temperature for your fish to thrive. It is capable of maintaining a consistently cool temperature. It uses R410a refrigerant liquid and is therefore completely freon free. There is no annoying loud noise and it has an easy to understand LCD display to control its microcomputer operation.
There is a sizable refrigeration capacity of between 26 and 80 gallons and it can chill 80 gallons of water by 15 degrees F. If your aquarium holds only 26 gallons, it will chill it by 30 degrees F over 20 hours as it has a high flow rate of between 264 and 660 gallons per hour. Because the evaporator is made from pure titanium, it does not corrode and can therefore be used with both fresh and saltwater.
Uses R410a refrigerant liquid
Chills 26 gallons by 30 degrees F over 20 hours
Can be used with fresh and saltwater
Maintains a constant temperature
Very easy to set up and operate
May not be adequate if extensive cooling is required
Have to purchase separate pump
May not start up at exact temperature set
This is a compact and useful quarter HP chiller for your aquarium that will lower the temperature in your tank and then maintain it. You set it to your desired temperature using the digital LED display that also allows you to monitor the temperature. There is also a memory recall system so the unit will return to the last set temperature if you are unlucky enough to suffer a power outage.
It has a high heat removal (BTU) rating which gives 25% more BTU per watt than many comparable chillers. The advanced titanium heat exchanger is corrosion resistant and will not freeze thanks to the anti-freezing system. The unit uses DuPont cooling agent which is environmentally friendly and, because the condenser is so efficient, it uses less energy. There is an automatic power surge shut-off feature. You will be able to set it up in minutes and you can remove the front condenser grill and the filter for easy cleaning.
Digital LED display
Memory recall system
Automatic power surge shut-off
High heat removal (BTU) rating
Clear display and easy to operate
Uses little energy so cheap to run
Produces a lot of heat
Doesn’t kick in until two degrees above set temperature
Compressor is running most of the time
An effective solution for temperature regulation issues within your aquarium. This fish tank chiller will work well in smaller aquariums. It has a quiet operation and is both reliable and efficient thanks to the advanced thermoelectric technology. It runs on electric power which is converted to cooling power to reduce the temperature of the water. You can bulkhead it through a one and a quarter inch gap in a siphon overflow or it can easily be fitted to prefilters and sumps. You can fit it directly into plastic aquariums.
The chilling action is continuous so there is no on/off switch to worry about however, you will need to use a separate temperature controller to control when the chiller is turned on and off to maintain your required temperatures. The device is capable of chilling 10 gallons of water by around six or eight degrees F. In larger aquariums, it can chill 20 gallons of water by three or four degrees F or 40 gallons of water by just one or two degrees F. Therefore, you may need to use multiple units if you have a large aquarium.
Very flexible about where it will fit
Needs a separate thermostat
Can chill 10 gallons of water by around six or eight degrees F
Reliable and efficient
Provides rapid cooling in a small aquarium
Virtually silent operation
Prevents sudden temperature changes
Produces a lot of heat
Not powerful enough to drop the temperature by a large margin
Will not be suitable for larger tanks
This 1/15th HP aquarium chiller has a clear digital LED temperature display that gives the temperature in degrees F and can be read easily in the day or at night. It can be used to effectively chill up to 40 gallons of water.
The fish tank chiller can be easily fitted in series in your circulation system and takes just minutes to install and set up. It has a highly advanced operation but is very quiet. The condenser is highly efficient and uses very little energy, saving you money. It has titanium refrigeration coils which are both highly efficient and resistant to corrosion. The unit has a small foot print and has a very compact design.
Will chill 40 gallons of water
Quick and easy to install and set up
Highly efficient and quiet
Titanium refrigeration coils resist corrosion
Very quiet operation
Works well in a 55-gallon tank
Some reliability issues
Unit runs constantly
This aquarium cooler is a fan that is designed to fit on the wall of your aquarium and slots onto the lip around the top edge. One fan is sufficient for a 10-gallon aquarium but you can use several fans together for bigger tanks. It is capable of reducing the water temperature by around two to four degrees C.
It would be very useful to use when you need to cancel out the heat created by lights or UV filters. The fan has a variable speed setting and has a wide-angle adjustment. It fixes to the aquarium using a clamp that is both stable and strong. It simply clips on and there is no complicated set up required.
One fan needed for a 10-gallon tank
Reduces temperature by two to four degrees C
Variable speed setting
No set up required
Maintains a steady temperature
Saves money on chilling
Will not fit onto all tanks
You can set up this fan chiller in seconds as it requires no assembly and comes with an AC adapter. All you have to do is use the clamp mounting bracket to fix it to your aquarium wall. It is compatible with aquariums that have walls up to 15mm thick.
It will help to increase the longevity of your aquarium lighting system by dropping the temperature yet it uses little power and is cheap to run. You can use it on tanks that have up to 32 Liter capacity and will lower the temperature by one or two degrees. It needs to be cleaned regularly and has a working temperature of below 26 degrees.
Very quick and easy to set up
Clips onto aquarium wall
Cheap to run
Reduces temperature by up to two degrees
Perfect for smaller tanks
Very quick to set up
Maintains an impressive cooling effect
Takes a while to reduce the temperature
Clips do not always work
This is a cost-effective solution to aquarium cooling. It is a set of two compact fans that have a two-speed control. They are capable of reducing the water temperature by around two or three degrees C. They fit onto the aquarium using adjustable jaw clamps and will suit any aquarium with walls up to 1.2cm thick.
This aquarium fan requires a 12V power supply and is manufactured to the highest safety standards. It includes a bracket so that you can adjust the direction of the fan by up to 100 degrees. This product is very quick and easy to install and can be moved from one aquarium to another with ease. They are particularly useful to prevent aquarium equipment from heating up the water. The operation is quiet and they can be used with saltwater aquariums and fresh water aquariums. They use only a small amount of power.
Cheap to purchase and run
Quick to install
Direction of fan can be adjusted
Will fit to most aquariums
Effective at dropping temperature of water
Very useful to have two speeds
May drop temperature too far if left running for days
Will not work with tanks with a black rim
A combined chiller and pump that will help you to maintain a suitable temperature in your aquarium. It has half inch fittings and requires a 120 V-60 Hz/264 watts power supply and is 1/10 HP. The pump will circulate 66 gallons per hour to a maximum of 317 gallons per hour.
The device has a built-in microcomputer that lets you know what is going on with a digital LCD display that is clear and easy to read. It can be used with fresh or saltwater aquariums. The chiller uses a titanium heat exchanger which gives optimum performance and which will resist corrosion. It also features a high-quality compressor so it is both efficient and very reliable.
Combined chiller and pump
Requires a 120 V-60 Hz/264 watts power supply
Built-in micro computer
High quality compressor
Doesn’t need a separate pump
Does not rust
Can get very hot
Instructions not very clear
You won’t have to worry about daily fluctuations in water temperature with this nano chiller which uses advanced technology to keep your aquarium cool. It includes a built-in thermostat that can be programmed to between 45 degrees F and 90 degrees F.
It can be effectively used to cancel out the heat generated by pumps, high-intensity lighting and UV sterilizers which can make your aquarium water much too warm. It is just right for nano tanks and for aquariums that hold up to 30 gallons. It uses advanced thermoelectric technology developed by NASA. In a 10-gallon tank, it will drop the temperature by 10 degrees F and in a 30 gallon tank it would drop it by two to four degrees F.
Maintains a water temperature of 45 degrees F to 90 degrees F
Cancels out heat created by lighting
Suitable for tanks up to 30 gallons
Advanced thermoelectric technology
Easy to adjust temperature
Maintains a steady temperature
Perfect for smaller aquariums
Will not be able to maintain a very cold temperature
Not suitable for larger tanks
You can use this highly efficient aquarium chiller with fresh or saltwater. The kit includes 100W chiller that will circulate water at a rate of 1-3 Liters per minute and a chiller that will cool your aquarium water. It works well with tanks up to 35 liters capacity. The system is controlled by a micro-computer and uses a semiconductor for the cooling effect. This reduces the amount of power that it uses and makes it highly efficient.
It features a large LCD screen and it has LED lights to indicate what is happening with the intelligent temperature control. It is very quick to set up and you can easily adjust the start and stop temperatures which can be anything from 10 degrees to 40 degrees C. The evaporator is made from an aluminum-alloy which is durable and will not corrode. It has a quiet operation and will display temperatures in both degrees C and degrees F.
Combined pump and chiller
Pumps at 1-3 Liters per minute
Intelligent temperature control
Easy to set up
Uses little electricity
You don’t need a separate pump
Instructions are hard to follow
Takes a while for the temperature to drop
Before you go out and buy an aquarium chiller, check out this list of the things that you should look for.
Your first decision is whether you want an aquarium water chiller that will cool the water or a fan that will blow air across the surface of the water. Fans are great for canceling out the effects of hot lights but for maintaining a steady low temperature in a larger aquarium a chiller will be best. These have refrigeration plates over which the water is passed so they work with a pump.
If you decide to get a chiller, there are two types that you can look out for. In-line chillers are best for larger tanks with in-line filtration and they will cool filtered water. They are also best for use with saltwater reefs. Drop-in chiller probes go in wet/dry filters or sumps. They are mostly used with saltwater reef setups and come in many sizes and powers. They are quicker to set up because they have no plumbing.
The power of in-line chillers is usually given in HP and they range from 1/5 HP to 1/3 HP. You need to get one that will suit your size of aquarium. They take a while to set up as they have to be plumbed in and they are not meant to be transported from one aquarium to another.
Check that the chiller is capable of maintaining the temperature range that you need it to.
If the chiller is very noisy to can get annoying.
Every aquatic species has an optimum temperature at which they do best and thrive. If your aquarium is operating at above this temperature, they will struggle to survive. When the water in an aquarium becomes too hot, there will be less oxygen dissolved in the water and this is not healthy for the plants or the animals in the tank. It is a particular problem at night and when ambient temperatures are warm. Shrimps, in particular, can suffer damage to their immune system when the water is too hot.
It is not just species from temperate or arctic climates that require aquarium cooling. Subtropical species require water to be at 18 to 25 degrees C and will suffer severely in a heat wave if the air temperature reaches 30 degrees C. Also, even some tropical species prefer cooler waters if they naturally live at deeper levels where the temperatures are cooler.
Here are some of the main benefits of a fish tank cooler.
There are two main types of aquarium chillers. The first type is basically a fan that blows air across the top surface of the aquarium. You can use just one fan or you can use multiple fans next to each other. The fans are small and are attached to the rim of the tank using a clip.
They work using the principle of evaporation which cools the surface that the water is evaporating from. They can be very useful for preventing lights from overheating. They do not chill the water itself and may not be effective in very warm ambient temperatures or for very large tanks.
The second type of aquarium chiller is a refrigeration device that actually cools the water in the aquarium. These tend to be more expensive and take a little longer to set up. They work by passing the water over cooling plates so you need to pump the water around. If they do not come with a pump, you will need to fix them up in series with an existing circulation system or buy a separate pump.
Your aquarium chiller will come with instructions and it is important that you follow these carefully. Drop-in chillers are very easy to set up as you literally just drop them in. However, in-line chillers are more time-consuming to set up. To install an in-line chiller, you will need a feed pump, an installation unit and hose clamps.
Your aquarium will probably have a reservoir in the bank where the majority of the filtration is housed. The best plan is to embed a feed pump into the reservoir and it will normally fit here very well. All you have to do is append the U-tube using a hose clip and put it in the reservoir. Then, just run the tube from the pump to the chiller inlet. After this, you run the tube from the chiller’s outlet into the aquarium. Finally, connect the tubing using an S-tube which will hang down the back of the aquarium. Double check everything and then set the desired temperature. It can take a day for the temperature to stabilize.
A: Aquarium chillers are devices that reduce the temperature of water in an aquarium so it matches the preferred temperature of the species that you are keeping there. They can simply be fans that blow air across the surface or they can be refrigeration plates across which the water is pumped.
A: Aquariums can over heat for many reasons. Humans like their houses to be warm and this may be too warm for the species that you are keeping. There may be sudden increases in ambient temperatures – heat waves. Also, the equipment associated with aquariums (such as pumps and lights) can give out a lot of heat and this can heat up the water.
A: In-line chillers are usually placed in the reservoir in the bank where most of the filtration equipment is housed. Drop-in chillers have a probe that goes into a wet/dry filter but it can go into any filter with a sump. Fan-type chillers are clipped to the top of the tank.
A: Most manufacturers will give instructions on cleaning. The mesh filters on the chillers should be vacuumed or brushed weekly. Once a year, a compressor should be used to clean out the chiller plates.
Our top pick of the best aquarium chiller is a quarter HP chiller using R410a refrigerant liquid and is therefore completely freon-free. It is quiet and has an easy to understand LCD display to control its microcomputer operation.
The refrigeration capacity is 26 to 80 gallons and it can chill 80 gallons of water by 15 degrees F. It has a high flow rate of between 264 and 660 gallons per hour. Because the evaporator is made from pure titanium, it can be used with both fresh and saltwater.