The 6 Best Aquarium Chillers for Maintaining Ideal Water Temperature

by | Blog, Articles, Breeding and Care

1. Introduction

Summer or seasonal warmth can cause severe discomfort for fish if they’re left at room temperature, especially in places where it gets quite hot. In those places, having an aquarium chiller is mandatory to keep your fish alive. Aquarium chillers help reduce the temperature of an aquarium (the opposite of what an aquarium heater does).

Tropical fish can tolerate warm water temperatures, since their native environments have similar conditions. Still, there are plenty of times when it’s too hot even for tropical fish, and you need an aquarium chiller to cool down the tank and keep it inhabitable.

Temperature control for aquariums using heaters and chillers is essential to keep the tank temperature stable and safe for your fish. I’ve put together a list of what I think are the best aquarium chiller options out there, along with lots of details and buyer feedback, to make your decision-making easy!

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2. 5 The 6 Best Aquarium Chillers: Reviewed

2.1 Poafamx Water Chiller

Tank capacity: 16 Gallons

Dimensions: 15.5 x 11.8 x 8.8 inches

Weight: 10.18 pounds

Best for: Tiny tanks, Avoiding refrigerants


This particular unit is a great option for small-sized fish tanks of up to 16 gallons. The Poafamx Water Chiller operates without a compressor and uses electronic refrigeration technology that doesn’t require adding refrigerants. The temperature sensor attaches to the aquarium, and the temperature settings can be programmed using the display.

The Poafamx kit includes a water pump that can be easily disassembled for maintenance. This aquarium water chiller can lower the water temperature by 2-5 °F. When the temperature is at its optimal range, the turns off – And when the temperature rises beyond the set temperature, it turns back on. (In other words, it has an automatic thermostat.)

This is a REALLY good feature to have because it will prevent over-cooling of the aquarium water.

Customer Sentiments

With over 66% of buyers rating this product with 4 stars or more, this aquarium chiller is a contender. Buyers found that the unit can cool water accurately to the required set temperature, and that the product’s finish is high quality. Some buyers found that it takes a considerable amount of time for the temperatures to lower the fish tank, and that wouldn’t work for anything larger than 16 gallons. (That last part is fair, though, as it’s rated for a maximum of 16 gallons anyway!)


  • Has an automatic thermostat that turns on/off.
  • Has a display.
  • Easy to disassemble the pump.
  • Instructions provided.


  • Takes time for water to reach the required temperature.


2.2 Active Aqua Water Chiller 1/10 HP

Tank capacity: 40 Gallons

Dimensions: 17 x 10 x 15 inches

Weight: 30.3 pounds

Best for: Fast cooling, Large tanks


Active Aqua offers water chillers with different horsepowers to suit a range of tank sizes. Here, I’m reviewing the 1/10 HP version, which is ideal for tanks up to 40 gallons in volume.

This unit uses R134a refrigerant for cooling and is (blissfully) silent during operation. A user-friendly control panel is equipped to control and manage the temperature as needed. I have to say that this brand of aquarium chillers has improved its products: They now offer a “boost” function that accelerates the chilling process to reach the desired water temperature faster.

Note that this is not a complete kit as it doesn’t include the pump and tubing needed to function (you’ll need to purchase separately). The recommended pump flow for this aquarium chiller is between 132 to 396 GPH.

Customer Sentiments

To date, this particular aquarium chiller has an overall rating of 4.5 stars from over 300 customers. Buyers are satisfied with how quickly it cooled the aquarium, and ease of set up, and loved how silent it is. Worth noting that a few people had problems with the unit not working, but that the seller was responsive and provided replacements. (This is why the unit still made it on the list:)


  • Can be used in freshwater and saltwater aquariums.
  • Quiet operation.
  • Has a convenient control system.
  • Good customer service.


  • The pump isn’t included.
  • Hoses aren’t included.


2.3 Datoo Aquarium Chiller

Tank capacity: 40cm tank

Dimensions: 8.5 x 5.3 x 3.1 inches

Weight: 1.25 pounds

Best for: Manual cooling/no refrigerants, Easy operation


The Datoo Aquarium Chiller consists of 2 aquarium fans that attach to the rim of the fish tank, blowing air into the aquarium water. When the fans blow cool air constantly onto the water, heat dissipation takes place.

The fan coolers are powered by a 12v DC power supply known to be energy-efficient and safe. Two wind speeds are available, which can be selected based on the surrounding temperature and how much cooling you need. The fans attach with adjustable clamps that can be fitted onto tanks up to 1.2cm in thickness.

I think it’s a great option, although I would be careful if you have lots of nano fish that are prone to jumping. The fans have a plastic housing, but freak accidents could happen in theory. (That said, I haven’t read any accounts of this happening with this product! I just play it super safe:)

This unit can drop the temperature by 4 to 6 degrees F, can be used for freshwater and saltwater fish tanks, and also comes with a 1-year warranty by its seller!

Customer Sentiments

With a rating of 4.2 stars by over 1750 users, this is a top pick for a fan chiller. Most buyers found it to effectively drop the temperature as required. Although the fan is designed to operate outside of the water, I came across a few buyers who accidentally dropped the unit into the water, but found that after drying it out, it still worked as usual. That said, don’t go dropping it willy-nilly in the water; This can cause rust in the circuits after contact with water, which will speed up the wearing of components.

The only downside is that it doesn’t fit tank rims beyond 1.2mm, so you’d need to create an adapter if you had a thicker tank edge.


  • Can be used in freshwater and saltwater aquariums.
  • Energy-efficient and safe.
  • 1-year warranty and cash-back guarantee.


  • Inability to attach to thicker tank edges.
  • Need to be careful with nano fish that may jump.


2.4 JBJ Aquarium Chiller Arctica Titanium 1/10 HP

Tank capacity: Up to 130 gallons

Dimensions: 13 x 19 x 20 inches

Weight: 41 pounds

Best for: Effective heat exchange, High-tech option


I picked this particular aquarium chiller as it’s a bit more advanced compared to some of the others. The JBJ Arctica Titanium Aquarium Chiller uses a titanium heat exchanger for maximum contact exposure while still being energy-efficient. Since titanium coils are corrosion-resistant and effective heat exchangers, they’ll allow your tank to maintain a stable water temperature.

An anti-freezing system does exactly what it sounds like: It protects the tank from extreme temperature drops and prevents freezing of the heat exchanger. The unit also has a memory chip, which helps to restore the last set temperature after a power failure. This can be vital to protect your fish if you’re not there when the power goes out.

With this option, you don’t have to program the temperature every time the power has been disconnected, which is nice.

Plus, the JBJ chiller also has an LED controller for convenience.

Customer Sentiments

With a rating of 4.2 stars out of 5, most buyers are satisfied with their purchase. They particularly loved this chiller’s ability to maintain constant temperatures, and repeatedly mentioned that it’s worth the cost because of the stable cooling it delivers.

Buyers who have used this chiller unit have often mentioned that it was worth the cost, due its positive performance. The only downside is that some found it to be loud. Others felt like it was more of a hum.

Also, be aware that the pump isn’t included and must be purchased separately.


  • Energy-efficient.
  • Corrosion resistant, with anti-freezing system.
  • LED controller
  • Temperature memory saved & restored from power shut-off.


  • Creates a slight noise.
  • The pump isn’t included.


2.5 Hamilton Technology Aqua Euro Max Aquarium Chiller 1/4 HP

Tank capacity: Up to 170 gallons

Dimensions: 14 x 10 x 14 inches

Weight: 30 pounds

Best for: Effective heat exchange, High-tech option for extra-large aquariums


The Hamilton Technology Aqua Euro Max is a modern and well-built aquarium chiller that offers some key features that are very helpful for maintaining stable aquatic conditions. This unit has a digital-LED screen that displays the water temperature, and a titanium heat exchanger that’s protected by an anti-freezing system (to prevent excessive cooling power).

As with the JBJ chiller, titanium heat exchangers are corrosion-resistant and ensure efficient cooling of tank water. The high BTU (heat removal) helps heat transfer from the water more efficiently while consuming minimum power. Like the JBJ, the Hamilton Technology Aqua Euro Max also saves the desired temperature so that in case of power disruption, the chiller restarts and targets the same temperature you’d had it set for.

Also like the JBJ, the Hamilton doesn’t have a pump (which needs to be purchased separately). The key differences between the two is that the Hamilton will work with larger aquariums (up to 170 gallons) and the JBJ works in tanks up to 130.

Customer Sentiments

With a rating of 4.4 stars out of 5 by its users, most buyers are pleased with its quiet operation and efficient cooling process for curtailing warm aquarium water. Nevertheless, some customers complained that it isn’t silent and creates some sound when the cooling system turns on and off.


  • Low power consumption.
  • Temperature settings saved.
  • It can be used for freshwater tanks and saltwater aquariums.
  • Works for tanks up to 170 gallons.


  • A pump isn’t included.
  • Creates some sound.


2.6 Baoshishan Aquarium Chiller

Tank capacity: Up to 42 gallons

Dimensions: 13.39 x 7.87 x 11.81 inches

Weight: 13 kg

Best for: Convenience, Small-to-medium tanks (Top pick!)


The Baoshishan Aquarium Chiller is a good option for tanks up to 42 gallons, putting it right in the mid-range size on this list. Titanium coils ensure effective heat exchange while resisting corrosion for more extended durability. The digital screen and panel make it easy to enter the required temperature.

This aquarium chiller contains two fans and holes for the expelled heat to be emitted. This enables heat dissipation, which helps the compressor as it works throughout the day. With R134a refrigerant, a cooler temperature can be achieved quickly. This chiller is can be used in either a freshwater or a saltwater fish tank. It also includes a pump!

Customer Sentiments

This unit in particular has very high ratings, with 4.6 out of 5 stars. Buyers are impressed with the product, found it easy to set up, and loved the excellent customer service, who responded to queries and initiated warranty replacements as needed right away. Some said it creates a light rumble sound that can disturb some people if used in a bedroom.


  • Can be used either in a freshwater tank or a saltwater aquarium.
  • Pump is included.
  • Great customer service
  • One-year warranty.


  • Makes a slight noise.

Top Pick

My top pick for aquarium cooler for a small-to-medium tank is the Baoshishan Aquarium Chiller. The primo customer service is what really weighed the scales in this product’s favor. I’ve dealt with enough annoying warranty situations to value highly a seller who responds quickly and resolves questions and queries well.

Please note that different tank sizes will require different chillers, so I’ve done my best to indicate in the “Best for” section of each chiller above what my top picks are for each!

3. Buying Guide For the Best Aquarium Chiller

Features are great, but first, know what you need. Below are considerations when it comes to choosing which aquarium chiller to purchase, so you make sure to get one that will work for your tank’s specific requirements:

3.1 Aquarium Size

Each aquarium chiller is designed for a particular tank size, so you need to choose one that’s compatible with your tank’s volume. Aquarium chillers also have recommended pump flow rates specified in their listing or packaging; It’s essential to follow this flow rate to ensure the success of its cooling system, as some aquarium chillers may require pump rates that would be too much for a particular tank size

For smaller aquariums, you can get smaller aquarium chillers and vice versa.

3.2 Ambient Temperature

The surrounding temperature is another vital factor to consider, as you’ll need to know how much the tank needs to be cooled. You can do this by first measuring the ambient temperature of your aquarium, and then comparing it with the fish’s requirements. Different aquarium chillers have different ranges of cooling. For example, some chillers can bring down the temperature by 3 degrees Celsius while some have the capability of reducing it by 5-6 degrees Celsius. After determining how much your aquarium temperature needs to be adjusted, you can choose a chiller accordingly.

3.3 Availability Of Space

Some aquarium chillers, especially external ones, can have large dimensions. Some contain fan coolers that absorb heat, and then the warm air is emitted through its ventilators. Such units must be kept away from the aquarium to prevent the heat from passing to the fish tank, so you’ll need a bit more space if you want one of these chillers.

4. Criteria For Selecting The Best Aquarium Chiller

Ice cubes

When ice cubes don’t cut it.

4.1 Chiller Capacity

This goes hand-in-hand with aquarium size. The chiller capacity is one of the most essential factors to consider. To ensure that the aquarium is adequately cooled, check that your tank size is compatible with the range specified on the product.

4.2 Types of Aquarium Chillers

Different tanks need different types of chillers. These are types of aquarium chillers that you’ll come across:

  • Condenser chillers use a water pump to suck in water, which will flow through a heat exchanger to make the water cooler. In my opinion, these are the most effective chillers and are also the choice of many experienced fish keepers.
  • Fan coolers are a popular type of chiller that are mounted close to the water surface. They work by blowing air into the aquarium water, which will help the temperature to fall by a few degrees. These are easy to use and require no effort to set up. For many people, a fan cooler is enough, but this will differ for everyone due to the changes in water temperature from one location to another.
  • Submersible coils are another type of aquarium chiller used in the aquarium hobby for cooling fish tanks. This involves placing the cooling coil into a sump or filter box, which will help reduce the water temperature in the aquarium. These aren’t the best solution for larger aquariums, but they can be suitable for small tanks without extreme temperatures differentials.

4.3 Difference Between Condenser Chillers and Fan Coolers

In reading theses aquarium chiller reviews, you probably noticed that there were some pretty drastically different designs mentioned! Aside from the fans that blow air on top of the water, there are two main designs to know: Condenser chillers, and fan coolers.

Condenser chillers look similar to a box placed outside the aquarium. In contrast, fan chillers are fitted inside the fish tank, but are not submerged.

A condenser aquarium chiller uses a water pump that helps circulate the water through the heat exchanger until the required temperature is met. Meanwhile, a fan cooling system will require manually switching it on till you find that the right temperature has been met. Fan coolers aren’t good for larger aquariums as they’re less effective for them.

4.4 Condenser Chillers

Condenser chillers are the most popular type of aquarium water chillers, and they’re reliable for providing a safe environment for aquarium inhabitants. A condenser chiller begins with the inflow of water, which will be later cooled using its technology. The cooled water will then flow back into the aquarium, cooling the water temperature. These are equipped with a built-in thermostat to ensure the temperature does not exceed the programmed level.


Aquarium thermometer: Water temperature


In addition to being a powerful cooling system, they are incredibly convenient as it assumes the responsibility of maintaining the temperature for you. That said, I still recommend having an additional thermometer to ensure that the temperature detected by the aquarium water chiller is accurate.

These aquarium coolers are sophisticated in design and contain many parts that might require to be replaced over time due to normal wear and tear, so I definitely recommend purchasing an aquarium chiller from a reputable brand that uses high-quality components. In most instances, such brands sell spare parts separately, which can be hugely helpful if they need to be replaced.

5. Factors That Can Impact The Performance Of A Saltwater Chiller

The high salt concentration in marine water causes metals to corrode, later breaking apart. Aquarium accessories often state whether it’s compatible with saltwater aquariums or not for this reason.

The water in a saltwater tank or reef aquarium will be sent through a heat exchanger in a condenser chiller. Therefore, purchasing one with corrosion-resistant components is vital for it to work without any issues. If not, a cooling fan can be used as it won’t be in contact with the tank water.

6. Best Options For Smaller Tanks

The best aquarium chiller for any fish tank will depend on its capacity, size, and requirements of the aquarium inhabitants. In general terms, I recommend getting aquarium fans for a small tank, or you can invest in a chiller with a compressor of a smaller capacity that matches the volume of your fish tank.

7. Frequently Asked Questions


Goldfish Photo

7.1 What Is The Ideal Temperature For Fish Tanks?

72 to 80 degrees Fahrenheit is considered to be the most optimal temperature by most aquarists. Most fish species are cold-blooded and can survive in cooling temperatures to a certain extent, but this is not a rule, and some fish are more sensitive than others.

7.2 Who Needs An Aquarium Water Chiller?

A water chiller will be crucial if your fish tank is located in an area with a hot climate or if temperatures rise rapidly during summer. Whether or not you need a chiller is dictated by whether or not your water temperature begins to rise towards the high end of what is appropriate for the species of fish you’re keeping. Water temperature in fish tanks can reach extreme temperatures, such as during heat waves. Having a chiller will prevent your aquarium inhabitants from suffering, and can even keep them alive.

7.3 How Do Marine Chillers Make The Aquarium Cooler?

They usually use the exact mechanism as in freshwater tanks. The main difference is the materials used in marine chillers, which must resist corrosion.

7.4 Is An Aquarium Chiller Worth It?

Yes. In comparison to most other aquarium accessories, chillers can be pretty expensive, I know. But it will ensure your aquarium stays at a safe temperature for your fish and plants. So, if the temperature is too high, yes, an aquarium chiller would definitely be worth it.

7.5 How Long Do Aquarium Chillers Last?

There is no exact answer to this, as it mainly depends on the quality of the product and how you use it. Usually, you can expect it to operate for over 4 years with good care.

7.6 What Size Chiller For A 40-Gallon Tank?

For this tank size, a chiller with a horsepower of 1/15 is suitable. There are aquarium chillers specifically designed for this tank size, which you can consider.

7.7 How Can I Keep My Aquarium Without A Chiller?

Having air conditioning will help maintain the water temperature, and you might not need a chiller. However, running air conditioners all the time can be costly. As a temporary measure, you can add some ice to a water bottle and place the bottle in the aquarium till the temperature settles – Though this is can be inconvenient to do repeatedly.



To say that I’m obsessed with all things saltwater is a bit of an understatement. Aquarium Passion has served freshwater and saltwater aquarium hobbyists for over 10 years, and I'm committed to keeping the information accurate and free. My post-bac certification in Sustainability informs my writing about aquarium conservation efforts. When I'm not writing at AP, I'm out in the ocean or researching weird fish.


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