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The Best Aquarium Chiller: Detailed Guide For Freshwater & Reef Tanks

Finding the best aquarium chiller for your tank needn’t be complicated. Read on and we’ll show you exactly what to look for to find the right one for you!

By Andy Birks
Last updated on

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best aquarium chiller

While tropical fish need warm water to thrive, often around 78°F, a tank that’s too hot can cause them just as much stress as one that’s too cold. So if you regularly get weather in the mid-eighties Fahrenheit, finding the best aquarium chiller for your tank is key.

Over the years we’ve used several chillers from various brands, and we brought that into our assessment of some of the top picks. Overall, we chose the JBJ Aquarium Arctica Titanium Chiller for its highly stable and accurate cooling of mid to large tanks.

Or if you need a budget option, Petzilla’s Aquarium Cooling Fans are fantastic for cooling a smaller tank by a few degrees.

But looking for the best aquarium chiller for your tank can be complex. That’s why we’ve provided a detailed guide of what to look for, so you can find the right one for your tank.

So let’s get started!

  1. Best Stable Cooling: JBJ Aquarium Arctica Titanium
  2. Best Value Condenser: BAOSHISHAN Aquarium Chiller
  3. Best Budget Cooling Fan: Petzilla Aquarium Cooling Fans
  4. Best For Large Tanks: Hamilton Technology Aqua Euro Max
  5. Best For Nano Aquarium: LONDAFISH Mini Aquarium Cooling Fan

Best Aquarium Chiller Picks Reviewed

This list includes some of the top inline condenser chillers for mid to large-size tanks, along with budget cooling fans for small aquariums. All have been reviewed against criteria including cooling capability, temperature stability, and efficiency vs. power (Hp).

1. JBJ Aquarium Arctica Titanium


  • Chiller Type: lnline condenser
  • Aquarium Capacity (US gallons): 1/10Hp = up to 75, 1/5Hp = up to 150, 1/4Hp = up to 200, 1/3Hp = up to 250
  • Dimensions (Inches): 18.5(d) x 18.0(w) x 18.0(h) (All models)
  • Pump Flow Rate (GPH): 1/10Hp = 240 to 960, 1/5Hp = 480 to 1320, 1/4Hp = 480 to 1920, 1/3Hp = 480 to 2420
  • Key Features: Anti-corrosive titanium coil evaporator, built-in thermostat with digital temperature control, digital display showing current/ set temperature, 2-year warranty
  • Best For: Stable Cooling

JBJ’s Arctica Titanium series are premium aquarium chillers, which is reflected in the price. But they do offer extremely efficient cooling. The refrigerant pipe is repeatedly coiled around the aquarium water pipe in the evaporator giving maximum contact for heat exchange.

Whereas a budget chiller rated at 1/10 Hp may struggle to cool a 75 gallon tank, the JBJ 1/10 Hp will easily cool this size to a steady 78°F without running constantly. So you’ll save electricity as depending on your room temperature it’ll only run a few times an hour.

There are several models in the series too. So whether you have a 30 gallon or a 250 gallon tank you can find the best aquarium chiller for your setup. Just use JBJ’s Chiller Calculator to find the right size based on your tank’s volume and desired temperature.

Each Arctica Titanium has an LCD display showing the current and set temperature. So you can easily read it from a distance and correct it if it’s running too high. You can calibrate the chiller too, making it more accurate. So you can ensure a precise temperature for your fish.

The built-in thermostat will automatically control the chiller and it’s accurate to +/- 1°F. So it will always keep the temperature cool and stable for your aquatic life. And while some owners report the Artica is not as quiet as expected, most praise its stable cooling and ease of use.

  • Highly efficient and stable cooling
  • Titanium evaporator safe for freshwater and saltwater tanks
  • Anti-freeze system prevents evaporator from freezing
  • Digital thermostat accurate to +/- 1°F
  • 2-year limited warranty
  • Unit is quite large
  • Cannot be housed inside an enclosed cabinet
  • Premium price

2. BAOSHISHAN Aquarium Chiller


  • Chiller Type: Inline condenser
  • Aquarium Capacity: Up to 42 US gallons
  • Dimensions: 13.3(l) x 7.8(w) x 11.8(h) inches
  • Pump Flow Rate: 159 to 211 GPH
  • Key Features: Anti-corrosive titanium coil evaporator, LED display with programmable starting and shut-down temperature, quiet running (30 to 40 dB), supplied with 159 to 211 GPH pump & 9.8 feet of tubing, 1-year warranty
  • Best For: Value Condenser

The BAOSHISHAN 1/10 Hp chiller can easily cool a 42 gallon tank by 8 to 10°F. And while other chillers of this size may cool up to a 75 gallon aquarium, this chiller is cheaper whilst still providing stable cooling.

With a room temperature of 85°F, you can maintain your tank anywhere between 75 to 80°F for freshwater tropical fish, or slightly higher for a reef tank. And some owners report it can go below 60°F in a 20 gallon tank, making it great for cold water fish too. 

As the BAOSHISHAN has a titanium evaporator, it’s safe for freshwater or saltwater tanks too, without the risk of corrosion.

We found this chiller maintains a very stable in-tank temperature. And the touch-button LED display allows you to set the start and shut-down temperature. So you can set a range such as 76 to 82°F, or a precise temperature depending on your fish.

At 13.3 x 7.8 x 11.8 inches it’s compact too. And while you need to allow about 6 inches around the unit to allow heat to dissipate, this is less space than some other chillers. So you should be able to fit it onto a 40 gallon aquarium stand without much trouble.

BAOSHISHAN provides a 159 to 211 GPH pump along with tubing. So unlike other chillers where you have to buy a separate pump, you’ll have everything you need to set it up. And if you do have a larger aquarium, you can choose the 1/3 Hp model for tanks up to 75 gallons.

  • Affordable price for an inline chiller
  • Can set start and shut down temperature for precise, stable cooling
  • Titanium evaporator for freshwater and saltwater tanks
  • Compact unit, with pump provided
  • 1-year warranty
  • Less cooling capacity per gallon than other chillers
  • Instruction manual not intuitive

3. Petzilla Aquarium Cooling Fans


  • Chiller Type: Aquarium cooling fan
  • Aquarium Capacity: 1 fan = 10 gallons, 2 fans = 20 gallons, 3 fans = 30 gallons, 4 fans = 40 gallons
  • Dimensions (Inches): 1 fan = 4.3(w) x 6.3(h) x 2.5(d), 2 fans = 8.0(w) x 6.3(h) x 2.5(d), 3 fans = 11.7(w) x 6.3(h) x 2.5(d), 4 fans = 15.3(w) x 6.3(h) x 2.5(d)
  • Key Features: 2-stage variable speed, easy to fit aquarium clamp, wide-angle 90° adjustment, 35 decibel noise level
  • Best For: Budget Cooling Fan

Petzilla’s cooling fans are a great budget option if you need to bring your tank’s temperature down by a few degrees. They come as a single fan for 10 gallon tanks, and up to 4 fans for a 40 gallon aquarium. So whether you have a nano or mid-size tank you’ll find one to fit.

We used the 2-fan setup on a 20 gallon tank and found they worked really well to bring down the temperature 5°F from 82°F to 78°F. Some users even report drops of 7°F. So they’re very effective if you have a small tank and need to deal with a short period of hot weather.

The clamps are easy to adjust and fix to the side of your tank. But bear in mind they will only fit on a rimless aquarium where the side is less than ½ inch thick. You can adjust the angle by up to 90 degrees too. So you can direct the fans at your water’s surface for maximum cooling.

There’s a 2-speed switch, so you can run the fans on high to increase the cooling effect. Or you can turn them down to the lower setting which is quieter. But at around 35 decibels (dB) they aren’t too loud for a cooling fan, so shouldn’t disturb you too much in your living room.

As with all cooling fans, they cool the water by evaporation. So you may have to top off your tank every few days. And some reef tank owners report that salt water can damage them after 3 or 4 months. But overall owners are impressed by their cooling effect at a low price!

  • Can reduce temperature by around 3 to 5°F for small tanks
  • Affordable & much cheaper than an inline chiller
  • Various sizes will allow cooling up to 40 gallon tanks
  • Quiet at just 35 dB
  • Less effective on larger aquariums
  • Salt water can cause damage after a few months
  • Can only be used on rimless tanks

4. Hamilton Technology Aqua Euro Max


  • Chiller Type: lnline condenser
  • Aquarium Capacity (US gallons): 1/4Hp = up to 170, 1/2Hp = up to 320
  • Dimensions (Inches): 1/4Hp = 17.5(d) x 13.0(w) x 17.5(h), 1/2Hp = 19.0(d) x 14.2(w) x 21.5(h)
  • Pump Flow Rate (GPH): 1/4Hp = 158 to 670, 1/2Hp = 315 to 795
  • Key Features: Anti-corrosive titanium coil evaporator, digital LED temperature display, anti-freeze system, 2-year warranty
  • Best For: Large Tanks

The Aqua Euro Max from Hamilton Technology is an incredibly powerful chiller. The 1/4 Hp model can chill a 170 gallon tank down by 10ºF or a 100 gallon by up to 30ºF. So it’s a great choice if you have a large tank and live in a hot climate with 95ºF summers.

If you have an even larger aquarium, the 1/2 Hp Aqua Euro Max is rated for tanks up to 320 gallons. Both models have a corrosion-resistant titanium evaporator, so are compatible with freshwater or saltwater aquariums too.

And like the JBJ Arctica, the Aqua Euro Max’s evaporator has an anti-freeze system. This stops the coils from solidifying with ice from condensation generated if it runs for extended periods. So you won’t have any issues with the evaporator breaking down.

The chiller has automatic surge protection so you won’t need a separate protector. And the automatic memory recall means all your settings will return after a power outage. So you can be confident your fish won’t overheat if there’s an outage while you’re out of the house.

With a footprint of 17.5 x 13.0 inches the Aqua Euro Max is not the smallest of chillers. And it doesn’t come with a pump so you’ll need to buy one separately. But overall owners of this chiller give it great feedback for its powerful and efficient chilling.

  • Powerful and efficient cooling for large tanks
  • Titanium evaporator with anti-freeze system
  • Surge protection and memory recall
  • Easy to remove front panel for cleaning
  • 2-year warranty
  • Unit is quite large
  • Not as quiet as some smaller chillers
  • Expensive

5. LONDAFISH Mini Aquarium Cooling Fan


  • Chiller Type: Aquarium cooling fan
  • Aquarium Capacity: Up to 20 gallons
  • Dimensions (Inches): 7.9(w) x 6.2(h) x 1.1(d)
  • Key Features: Double fan with 2-stage variable speed, adjustable clamp to fit ½-inch tanks, wide-angle 100° adjustment, 30-day guarantee
  • Best For: Nano Aquarium

At 7.9 x 6.2 x 1.1 inches, these dual cooling fans are compact yet powerful and very effective for up to a 20 gallon tank if you need to cool it by 2 to 4°F. Their small size makes them great for nano aquariums of 10 gallons or less too.

They have an easy-to-use adjustable clamp and are designed to fit rimless tanks less than ½ inch thick. Although some owners report they will fit a 20 gallon tank or smaller if it has a very thin rim.

The angle of adjustment is wide at 100 degrees. So you can easily direct them at any angle to your water’s surface to help control the cooling effect. And if you’re losing too much water to evaporation, you can reduce the angle to slow down the rate.

Like the Petzilla cooling fans, these fans have 2 speeds. So you can increase the power to affect cooling. Many owners praise these fans for lowering their tank temperature by around 2 to 4°F. But some owners report they can be fairly noisy, especially at the higher speed.

  • Compact size for 20 gallon and nano aquariums
  • Can reduce temperature by around 2 to 4°F for small tanks
  • Affordable cooling
  • 30-day money-back guarantee
  • Not effective on aquariums over 20 gallons
  • Will generally only fit rimless tanks
  • Can be noisy at high speed

Considerations When Looking For The Best Aquarium Chiller

Choosing the best aquarium chiller can be quite an investment for your tank. So it’s important to consider the factors below before making your decision.

Do You Need An Aquarium Chiller For Your Tank?

No matter what fish you have, it’s critical to keep a stable temperature. Coldwater fish like fancy goldfish prefer between 65 to 75°F, whereas many tropical species need around 74 to 80°F. And marine fish and corals often need higher, at about 76 up to 82°F.

large saltwater tank with liverock

But if your tank gets too hot it can stress your fish and weaken their immune system in much the same way as if your water becomes too cold [1]. Excessive temperature can also lower the oxygen levels in your water, as well as cause algae to thrive [2].

For many of us, an aquarium chiller isn’t essential. But if your tank or your room’s temperature frequently gets to 85°F or higher, you may need to look for the best aquarium chiller for your setup especially if you keep cold water fish.

What Can Cause Your Tank To Overheat?

Living in a warm climate with 100°F summers is one obvious way your aquarium can overheat, especially if you don’t have air conditioning. And even if you do, how likely are you to leave it running all day while you’re out of the house?

Another important factor is your aquarium equipment. Any powerheads, submersible pumps, or non-LED lighting can raise your tank’s temperature significantly. And the bigger your equipment the more heat it’s likely to produce.

How The Main Types Of Aquarium Chillers Work

Which type of aquarium chiller you choose will mainly depend on the size of your aquarium and the level of cooling you need. Let’s look at how the 3 main types of chiller work and what scenarios they’re suitable for.

Inline Condenser Chillers

These are the most common and efficient type as they draw heat directly from your tank’s water and work like an air conditioning unit. They can be used for small tanks, even down to 10 gallons, but are the best aquarium chiller if your tank is around 30 to 40 gallons or above.

The chiller sits outside your aquarium and draws the warm water into an evaporator coil inside the unit. Here a refrigerant absorbs the heat from the water and the cool water is returned to your tank. The refrigerant is compressed into a condenser coil where fans dissipate the heat.

As long as you choose the right spec for your tank (more on that later), inline condenser chillers can easily pull your tank down from 85°F to 78°F or lower and keep it stable. But they can be costly, and in many cases, you’ll need a separate pump to draw the water.

Aquarium Cooling Fans

Cooling fans are fixed to the rim of your aquarium and blow directly onto the surface of the water. As they only use evaporation to cool your tank they are not as efficient as condenser chillers, usually only lowering the temperature by 3 or 4°F.

They can also be quite noisy, especially if you have 3 or 4 fans running. But cooling fans are much cheaper than condenser chillers. So if you have a smaller tank and your room isn’t overly hot they can be a great option.

Probe Or Thermoelectric Chillers

Thermoelectric chillers are solid-state heat pumps that draw heat from one side of the device to the other using electrical energy. A metal probe is inserted into your tank which draws heat from the water into a heat sink at the back. A fan then dissipates the heat.

These chillers only have the power to be effective in 10 gallon aquariums or less. And while they are quite inexpensive, you either have to drill the side of your aquarium to insert the probe or hang the whole unit above your tank.

Factors Affecting Your Chiller’s Performance

Even the best aquarium chiller can have performance issues. But these are often caused by two factors. 

This first is choosing a chiller that’s not adequately sized for your needs. And the second is not situating and maintaining it correctly. Let’s look at these factors in more detail:

  • Ambient Room Temperature: If your room is likely to be significantly hot for a long period, such as around 100°F all summer, choose an oversized model. This allows the chiller to cope without constantly running which can lead to wear.
  • Heat From Equipment: Your aquarium equipment can generate a lot of heat. So factor this in when choosing your size and model of the chiller.
  • Placement & Ventilation: Condenser chillers remove heat from your water and expel it into the air. So make sure you provide at least 6 to 12 inches around the unit for ventilation and check the instructions before placing it in a cabinet.
  • Maintenance: As your chiller’s fans run, a build-up of dust and debris can clog the vents or grill. So gently vacuum them around once a month to stop the airflow from being obstructed, which can lead to your chiller being overworked.

How To Choose The Best Aquarium Chiller For Your Tank

At first glance, choosing the best aquarium chiller for your tank can seem complicated. But the main factors you should look for are the aquarium capacity of the chiller based on your tank’s size, and the temperature you want to reduce your water to.

Large aquarium with angelfish

We’ve summarized the other key specifications manufacturers will typically give but note this is a very rough guide as different chillers can vary greatly.

Aquarium Capacity (US Gallons)Compressor PowerBTU/ HrPump Flow Rate (GPH)
50 to 801/ 10 Hp1,000130 to 400
150 to 2001/4 Hp3,000400 to 900
250 to 3501/2 Hp4,000800 to1600
450 to 6501 Hp10,0001320 to 3900
Typical example values are shown. For precise specifications refer to the manufacturer’s guidance for each chiller.

The ideal way to choose the best aquarium chiller for your tank is to use an online chiller calculator or refer to the manufacturer’s sizing guides. But let’s look at each of these factors in more detail to help you choose the right chiller for your tank.

Size Of Your Tank

If you have a nano aquarium, or even a larger 20 gallon tank, you could choose to use cooling fans. But although cheaper, remember this solution is generally only effective if you need to cool your tank by 3 or 4°F.

For larger tanks and more efficient cooling the best aquarium chiller is an external inline condenser. Manufacturers will usually give the aquarium capacity each of their condenser chillers is designed for, often in a range such as 150 to 200 gallons.

Current And Desired Water Temperature

Manufacturers use a capacity range because, in addition to tank size, your current room temperature greatly affects the chiller’s cooling capability. But as long as your tank’s volume is within this range you should at least be able to cool your water by about 10ºF.

Some manufacturers indicate the cooling level for different water volumes. So for a tank at the lower volume, say 100 gallons, the chiller may cool by 30ºF. Whereas at its highest volume, 170 gallons for example, the cooling effect would be less, at around 10ºF.

When using an aquarium chiller calculator or sizing chart, always use the highest temperature your tank currently gets to. And where possible, factor in the heat from your lights, powerheads, and other equipment. You can usually find this given in Watts in the instruction manual.

Type Of Tank

When it comes to inline condensers many of the best aquarium chillers are freshwater and saltwater compatible. But again check the manufacturer’s guidance on your chosen model.

Make sure it has an anti-corrosive evaporator, usually titanium, as it’s this part of the unit that comes into contact with the water. This is particularly important if your chiller is for a marine tank to ensure the salt water doesn’t corrode it.

If you’re looking at a cooling fan for a smaller tank, make sure the fan can be mounted onto the rim. Many aquarium cooling fans have very narrow mounts designed to hook onto rimless tanks that are less than ½-inch thick.

Horsepower And BTU

Condenser chiller manufacturers rate their units in terms of horsepower and BTUs (British Thermal Units). While it’s aquarium capacity and desired temperature you need to focus on when choosing the best aquarium chiller, it can be useful to understand what these mean.

Horsepower (Hp) refers to the power of the compressor motor. A chiller with a greater cooling capacity usually has a more powerful motor. Chillers for tanks up to around 80 gallons are usually 1/10 Hp (one-tenth of a Hp). Some 1 Hp chillers can chill up to 650 gallon tanks. 

BTU (or BTU/ hour) is a measure of how much heat energy the chiller can remove from your water per hour [3]. These ratings can vary but typically a chiller for a 75 gallon tank may be rated at around 1,000 BTUs and for a 450 to 650 gallon tank it could be around 10,000 BTUs.

Flow Rate And Pump

Condenser chillers are designed to cool your water, but to move it from your tank and back again you’ll need a separate pump. Occasionally a pump may be provided, but usually, you’ll need to buy one.

It’s important to get a pump with the right flow rate (measured in gallons per hour or GPH), as this affects your chiller’s performance. 

Manufacturers will give guidance on the flow rate needed for the chiller, so choose a pump that’s within this range.

Noise Level

Inline condenser chillers are generally fairly quiet, although larger 1 Hp units can be a little louder. Choose a chiller that’s around 35 to 45 decibels (dB), which is quieter than background office noise, and it should run in your living room without disturbing you.

Cooling fans can be louder, so consider putting them on timers if you don’t want them to disturb you all day. But keep an eye on your tank’s temperature to check you’re still getting the cooling effect you need.

Price And Durability

Inline condensers can be costly. Smaller 1/ 10 Hp chillers can start around $400, with bigger units over $1000. But they are the best aquarium chiller for efficient cooling and temperature stability. Cooling fans are much cheaper starting at around $30.

Make sure your chosen chiller is going to be durable. One of the best ways is to check reviews and feedback from current owners on sites like Amazon. A good condenser chiller should last several years, and will often come with a 1 to 2-year warranty.

Our Verdict

Maintaining a stable temperature in your aquarium is critical to the life of your fish. And just as you need the right heater for a cooler climate, if your room often gets above 85°F you should look for the best aquarium chiller for your setup.

For powerful and stable cooling we recommend the JBJ Arctica Titanium Chiller. Its +/- 1°F accuracy will maintain the temperature range needed for your fish in a hot climate.

Or if you have a smaller tank and need to cool it by a few degrees, the Petzilla Aquarium Cooling Fans are great for short-term cooling from a 10 gallon to a 40 gallon tank!


We’ve answered the most frequently asked questions when it comes to choosing the best aquarium chiller for your tank. Take a look below!

How Do I Know I Need An Aquarium Chiller?

Tropical tanks should be around 74 to 80°F, with marine tanks not much over 84°F. If your room temperature is consistently over 85°F you may need a chiller.

What Is The Best Aquarium Chiller For My Tank?

Cooling fans are fine for small tanks if you want to lower them by 2 or 3°F. For tanks over 30 gallons look for the best aquarium chiller, such as the JBJ Arctica Titanium.

How Should I Maintain My Aquarium Chiller?

Vacuum the fan grill to remove dust, and check the inflow and outflow hoses at least monthly. Flush the hoses with a weak vinegar solution to remove any calcium buildup.

Are Aquarium Chillers Noisy?

Inline condenser chillers are fairly quiet with many around 35 to 45 dB. Bear in mind cooling fans tend to be louder though.

Photo of author
Andy Birks
Andy is the owner of Simply Aquarium and manages the team of experienced writers on the site. He loves helping fellow aquarists and introducing new people to the hobby!

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