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What Are The Best Water Chillers For Hydroponics?

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One of the common troubles Hydroponic growers face is the high temperature of the nutrient solution. The temperature is critically important, but most people overlooked.

Using a water chiller is the most efficient choice when it comes to bringing your system’s temperature down.

Gone are the days when water chiller possession is only limited in commercial production because of its high cost. Now many affordable but effective options are available on the market for indoor growers and hobbyists.

In this post, I will help you answer when you need a chiller, why you need it, and help you choose the best hydroponic water chillers on the market.


Quick Product Table

Our Rating
Top Pick

JBJ Aquarium Arctica Titanium Chiller

  • Top-end water chiller
  • Powerful and reliable performance
  • A variety of chiller sizes to choose
  • Online calculator for chiller size on the manufacturer’s website
  • 2-year warranty

5 out of 5

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Best Value

Active Aqua Chiller

  • Reliable manufacturer
  • Comes with up-to-date water chiller technologies
  • More affordable than JBJ Aquarium, and other chillers
  • 1-year warranty

4.5 out of 5

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Budget Pick

IceProbe Thermoelectric Aquarium Chiller

  • Measures just 9 x 0.5 x 8 inches in size
  • Works great for budget users and hobbyists in small water systems
  • Compact design
  • Silent running
  • 1-year warranty

4 out of 5

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What is a water chiller?

A water chiller is an external unit whose purpose is to lower the temperature of the system you install it to.

It often has a thermostat that measures and lets you know the temperature of the water in the container.

In fact, the word “chiller” is quite a misnomer term. You must understand how it works to know how it is not really a “chiller” – it does not bring or blow any cool or cold air, but remove heat instead.

Why use a water chiller?

Controlling temperature is one of the most effective ways to control your crop’ yield and performance.

The water and the nutrient solution are the heart of your system.

And temperature is one of the most common issues that happen in the water system.

Warm water decreases its ability to hold oxygen, which means less dissolved oxygen in the nutrient solution. This severely affects the root growth. Also, there will be more chances of diseases and pathogens.

Cooling the nutrient solution can be as easy as throwing some iced bottles to reduce the system’s temperature temporarily, but it’s not efficient and hands-off.
Fortunately, the water chiller, if you can afford it, is no doubt the best solution and can also fit any hydroponic and aquarium size.

When should you get a water chiller?

If you, human beings, need an air conditioner, your hydroponic plants need a water chiller.

Many factors could bring in a high temp in your system – the weather in your city gets too hot, especially in the summer; the pump runs continuously, causing lots of heat.

Grow lights emit heat too. And in fact, in a closed grow room area, they are the factor that causes the most heat.

A CO2 burner, air handlers, dehumidifiers also add heat to your system.

Keep in mind that the ideal environment for growing is
air temperature at 75 – 80F, and root zone at 68oF or less

If the temp of your system, where the roots stay has drifted too far of 68F, it’s time to chill it.

Pros and Cons of using a water chiller


Dissolved oxygen in the nutrient solution. Warmer environment decreases oxygen level, which in hands reduce the chance of living of any inhabitant living inside. If chilling is the primary purpose of water chiller, it has done the job absolutely well.
Automate the process. When your system is still small, you can watch and chill it manually when the heat rises. But what happens when you have a larger one, or when the ambient temperature has got out of control? It’s better that you get a water chiller and let it automatically bring the heat away without any hassle of checking or worrying about plant roots’ death.


Heat. The water chiller is actually a mini refrigerator. It puts out heat. That’s why you should not place it near the growing area to keep energy efficient.
Expense. In fact, the biggest reason against water chiller is it’s a quite an investment even though it has become much affordable over the years. Unless you are a commercial grower, hobbyists, or someone who know exactly how a water chiller can bring high ROI (return on investment) to your system, other inexpensive chilling methods can be used instead.

How to accurately size the chillers for your hydroponic systems?

Determining the size of water chiller beforehand is very important as you cannot use the same size of the chiller for all systems.
Oversizing it will make the chiller cycle more often. This will consume more electricity.
Meanwhile, an undersized one will never properly cool your system.

Cooling/Chilling ability is measured in BTUs (British Thermal Units) or Tons (BTU per hour/12000). One BTU will increase 1 pound of water by 1oF.

The higher BTUs a unit has, the quicker it removes heat than the one with a lower BTU.

Often, on their website, each manufacturer will list out the important areas to fill to calculate the sizing approximately.
If they have, you should check to know immediately the size that fits you.

But in case you want to find out the BTH/h you need to know the size you want, I will also give a specific guide here.

The process of sizing an exact BTU needed is quite complicated and tricky, and the truth is it cannot be 100% correct because there are lots of factors involved like heats of ambient rooms, grow lights, dehumidifiers, etc.

But spend a little time as it’s essential to check the approximate BTU you need for your system. And it is not hard to do the calculations.

Let’s compute the BTU per hour.
Here’s the formula:

BTU per hour = Gallons per hr x 8.33 (weight of a water gallon) x Temperature Differential (in an hour)

We’ll break down each unit.

BTUs per hour. We are measuring the BTU increased in an hour.

Gallons per hour, or flow rate of the pump per hour.

The temperature differential is the change in the incoming water temperature and the water temperature you desire. This is to compute how much heat all equipment add to the system in 1 hour.

For incoming water temperature, you should get the hottest temperature your nutrient solution can have on the hottest day, including all the heat from everything that can give off (like grow lights, pumps).

The desired temperature is the optimal one you want for your system. Typically, it would be about 60 – 68oF.

Now, time to give an example with numbers for clearer clarifications.

Let’s say I have a system of 50 gallons of water.
On its hottest day with all equipment turned on and all heat emitted, the temperature recorded is at 75oF.
Then, I bring down the system temperature to my desired one at 60oF by throwing some frozen water bottles not to add more water to the system.
Now, take away all chilling frozen bottle, and record the temperature after one hour. The temperature I measure is 70oF.

Now I have had the change in temperature within 1 hour: 70 – 60 = 10oF

Therefore, the BTU/h = 50 (the gallon of water) x 8.33 x 10 = 4165
You will need to back up in case your system can be hotter. We’ll add 20% to the total BTU/h.
Total BTU/h= 4165 x 1.2= 4998

If you want to convert into ton unit, here is the conversion formula:
Because 1 ton of cooling = 12,000 BTH/h, then 4998 BTH/h = 0.4165 tons

What about Horsepower unit?

Measuring in terms of BTH/h and tons makes it easier for customers to choose as it lets them know how many refrigeration tons of ice a water chiller can make.

However, in reality, it’s not the case.

You will see that most chillers sold on the market are measured in horsepower (HP). But horsepower only shows you the compressor size/capacity of the chiller. It just gives you an overall idea of how strong the system. It doesn’t tell you the actual converted energy provided with the actual temperature and the desired temperature you want.

In a technical explanation, horsepower and BTH/h are two different measuring unit to convert.
Horsepower is a power unit, letting you know how much power a machine consumes.
Meanwhile, BTH/h is a refrigeration unit, telling you the refrigeration rate of the machine per hour.

So when you say 1 HP = 9000 BTH/h, it should be put correctly that with the refrigeration rate at 9000 BTH/h, the machine power of the chiller is 1 HP.

Because HP and BTU/h are different units, that explains why 1 HP can be converted to different BTU with different chiller machines. The higher each HP can be changed into BTU, the more energy efficient your chiller is.

For example, Some water chillers only have 9000 BTU/h for 1 HP.
Meanwhile, another can bring in up 12000BTU/h for 1 HP because it owns an efficient technology.

So if the manufacturers disclose BTH/h or ton, you can follow our guide above. They are a more accurate way to know how good a water chiller machine is.

If they only disclose the HP,  you can follow the manufacturer’s recommendations for the gallon sizes.

Or you can just guess how many BTUs for each HP. Commonly, 1 HP = 9000 -> 12000 BTU/h (depending on the technology and how efficient it is).

Let’s say if you calculate that you need 4998 BTH/h, you’ll need a 0.4 – 0.5 HP chiller machine.
To be safe in case my system is larger or hotter in reality. I’ll get a 0.5 HP water chiller.

Top 5 Water Chiller for Hydroponics

Top Pick

JBJ Aquarium Arctica

Titanium Chiller

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  • Size 1/15 HP
  • Recommended chiller sizes 1/15hp – 40 gal
    1/10hp – 130 gal
    ⅕ hp – 180 gal
    ¼ hp – 260 gal
    1/3hp – 340 gal

The JBJ comes with a powerful water chiller machine that produces little noise when running.
This product is also appropriate for freshwater and fishwater with its titanium cover.

Compared to other chillers, their design looks premium. But what I love the most about this product is it shows excellent care for the customers.
It is packed with a 2-year warranty while most products on the market cover only one year.
It also has an online website that helps you choose the chiller size you need by entering some figures for it to give you a specific number.

This water chiller comes with most of the latest technology for a water chiller – Its built-in thermostat helps turn off chilling when the system reaches the set temperature. A temporary memory helps keep the last set figure in case of a power cut.

It is more expensive but more powerful than other products.

There’re some complaints about the quality of some products, so you must get it from a reliable supplier.

  • Quiet and efficient performance
  • Reliable manufacturer in the chiller industry.
  • Many sizes to choose.
  • Long warranty period
  • Online calculator, convenient for customers
  • Some products have defects. So always be sure to get from a reliable supplier
  • More expensive
  • Do not come with pumps and hose. So need to buy them separately

Best Bang for Your Bucks

Active Aqua Chiller

Active Aqua Chiller

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  • Size 1/10 HP
  • Recommended chiller sizes 1/10 HP for 13 – 40 gal
    1/4 HP for 26 – 80 gal
    1/2 HP for 52 – 132 gal
    1 HP for 80 – 250 gal

Active Aqua Chiller is marketed among hydroponic growers. That’s why it’s relatively popular among hydroponic hobbyists as well as commercial production.

This product is freon free, friendly to the environment and comes with an LCD display where you can set the temperature you desire and check the progress. There is also a temperature control that will turn off the fan once it reaches the set temperature

It comes with some types of tubing size: 1/2″, 3/4″, and 1″, depending on the chiller size.
The produce is built with different sizes from 1/10hp to 1hp, which can accommodate up to 250 gallons.

  • Good design. Easy to install
  • Made for hydroponic growers
  • Reliable brand
  • Latest chiller technology (LCD screen, temporary memory chip, efficient compressor)
  • Better price than other chiller brand names
  • Inconsistent build. Some products have sensor problems. Should get from reliable suppliers.
  • Do not come with water pumps and hoses.

Budget Pick

IceProbe Thermoelectric

Aquarium Chiller

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IceProbe Thermoelectric Aquarium Chiller – 4 in. x 4 3/4 in. x 7 1/2 inFor hobbyists, the IceProbe seems to be the perfect option for a more comfortable price. But that also means this water chiller can only fit small water system.

The manufacturer and real-life using also suggest that you should not use the IceProbe for more than 10-gallon hydroponic or aquarium system with chiller temperature not greater than 8oF. Should you want to chill faster or need to use with a larger system, you should get more than one device or purchase water chillers from other manufacturers.

This chiller uses the thermoelectric cooling technology. It removes heat by emitting it into the ambient environment via its fins cooled by a low-speed fan. No pump, no compressor is used. And even no temperature controller to turn off machines when the temperature is in place. So you need to buy a separate one.

  • Great for hobbyists and budget users for small systems.
  • Small, compact chiller.
  • Quiet performance.
  • No water pump needed
  • Only suitable for small tanks.
  • Rough and not premium-looking design
  • No temperature controller

Other Choices

Hamilton Technology Aqua Euro

Max Aquarium Chiller

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  • Recommended chiller sizes 1/13 for 30 – 50 gal
    1/10 HP for 50 – 80 gal
    ¼ HP for 80 – 170 gal
    ½ HP for 170 – 320 gal
    1HP for 320 – 700 gal
Hamilton Technology Aqua Euro Max Aquarium ChillerThe Hamilton chiller is another chiller product that is more popular among the aquarium growers. It is really powerful with 1/13 hp can accommodate up to 50 gals.
Packed with an LCD screen monitor for easy monitoring and setting, this chiller uses the environmentally-friendly Dupont ozone refrigerant.
Its anti-freezing system helps prevent the heat exchanger from freezing, which affects the memory recall and the whole system.
The 1/13 HP is stated to have 800 BTU, which can be used for up to 50-gallon water system. It can reduce an average of 10oF for 50-gallon tank, and 20oF for 30-gallon tank.This chiller also comes with various Horsepower suited to any size.
It does not come with pump and hose. So you have to buy separate ones instead.
  • Easy to set up and use.
  • Well built.
  • Powerful performance.
  • Advanced technology (temporary memory chip, Dupont ozone refrigerant, LCD screen)
  • More expensive than other types.
  • Some noise when running, like a refrigerator running.

Ecoplus Chiller

EcoPlus Chiller, 1/10 HP

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  • Recommended sizes 1/10 HP – 40 gal
    1/6 HP – 60 gal
    1/4 HP – 80 gal

Ecoplus is another common chiller among hobbyists commercial hydroponic growers that comes with a really sensible price. But it is not as popular as the Aqua.

Just like the Aqua chiller, it is a good machine with LCD display, temporary ic chip. Its price is competitive than other types but is less powerful than.

There are lots of sizes to choose for both hobbyists, small growers, and commercial gardeners/aquarium growers.

  • Relatively good price with its HP power
  • Latest chiller technology (LCD screen, temporary memory chip, efficient compressor)
  • Reliable manufacturer
  • Some growers have some defective products
  • Not as powerful as other types with the same HP

Wrapping up

Choosing a water chiller for your hydroponic system is not an easy choice with many options on the market. By spending lots of time for researching and talking to manufacturers, the JBJ Aquarium Arctica Titanium Chiller is our favorite chiller that is powerful, energy-efficient, long-lasting, and have a long warranty period.

If you are looking for a less expensive chiller but can produce excellent performance, the Active Aqua chiller is the perfect option.

The IceProbe is a perfect budget-picked chiller for hobbyists, and small hydroponic or aquarium growers.

small water chiller