JBL PROTEMP Cooler x300 (gen 2)
Cooling fan for freshwater and marine aquariums from 90-300 l

  • Cools water temperature by 2 - 4 °C at higher ambient temperatures: cooling fan with modern cross-flow fan and broad air flow for aquariums
  • Easy to mount on the aquarium edge: pane thickness max. 2.4 cm. Air flow direction freely selectable and casing on mount rotatable by 360 °. Connect with power supply unit and plug power supply unit into the socket - the cooler is on
  • Cool water through air flow at the water surface = evaporation cooling. Can be extended with JBL CoolControl temperature control. 2nd Generation: quieter thanks to improved fan wheel bearing
  • Safety: 12 V extra-low voltage, safety cover grid. Power supply for all common mains voltages worldwide. With adjustable air jet angle
  • Package contents: 4 W cooling fan for aquariums, power supply unit with 150 cm cable leading to the cooling fan. Cylinder fan wheel 18.5 cm wide; casing width 27 cm, casing height 6 cm
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Recommended retail price incl. VAT
You can find this item in your specialist and online shop
Product information

Temperature control
Two important factors affect the water temperature in the aquarium: firstly the room temperature and secondly direct sunlight. If the room temperature in summer increases significantly, it is important to check the temperature in the aquarium regularly. Aim for 24-26 °C. Temperatures above 30 °C are a problem and can cause substantial damage to fish and plants. And never expose an aquarium to direct sunlight. The higher the temperature, the less effectively the oxygen (which is vital for the animals) dissolves.

Easy to install
The bracket of the cooling fan is placed onto the aquarium rim (up to max. 2.4 cm thickness) and fixed with clamp screws.

Cools by evaporation
The JBL PROTEMP Coolers for freshwater and marine aquariums cool between 2-4 °C with the help of cross-flow fans. The air flow helps the warm water to evaporate at the water surface and thus generates evaporative cooling. This is comparable to the evaporation cooling effect when wet skin is exposed to the wind.

The water cooler has a safety cover grid and is operated with an extra-low voltage of 12 V.


JBL PROTEMP Cooler x300 (gen 2)

Art. no.:
EAN Code:
180 mm
for litres:
Volume packaging:
2.9 l
Gross weight:
519.3 g
Net weight:
379 g
Weight factor:
Packaging dimensions (l/h/w):
130/75/290 mm


Animal species: Arowana, Artemia, Axolotl, Barbels, Bettas, Bichirs/reedfish, Blowfish, Catfish, Cichlids (South America), Corals, Crayfish, Danions, Discus, Dwarf shrimps, Flowerhorn, Gobies, Goldfish, Gouramis, Guppy, Juvenile fish, Killifish, Livebearers, Loaches, Newts, Panchaxes, Rainbowfish, Snails, Spiny eels, Tetra, Veiltails, freshwater butterflyfish
Animal size: For all animal sizes
Animal age group: All aquarium and terrarium animals
Material: plastic (ABS) / metal (aluminium)
Colour: grey / black

Electronic label / illuminant

Mercury: No
Dimmable: No

Technical Data

capacity from - to:80-200l
capacity tank length:60-100 cm
power output in Watt:3 W
Height:60 mm
Length:180 mm
Width:60 mm
diameter:60 mm
voltage:230 V
How does the noise level of the new PROTEMP COOLER compare to the other coolers?

A lot of commercially available products, including our predecessor range, have two to four axial fans (depending on the model). The appearance is reminiscent of a PC fan. The design of the cross-flow fans used in the JBL PROTEMP COOLERS makes them run more smoothly and gives them a quieter air flow. Its one axis drive ensures a further reduction in noise. In models using similar technology, the bearing is typically based on sintered bushes. Thanks to a high-quality ball bearing, a dedicated bearing to give additional damping, plus a reworked bearing in the cross-flow fan wheel, the new PROTEMP COOLERS guarantee you greater stability. Rattling and squeaking are now a thing of the past.

Is rattling normal during operation?

The cross-flow fan provides an audible air flow that is uniform and must not rattle or clatter. However, if such a problem does occur, it could be an indication of damage from a fall or strong impacts on the enclosure wall. Check that the cross-flow fan is correctly mounted or if the housing is incorrectly assembled. If these are not the causes your ProTemp Cooler must be returned to the factory for inspection and repair by the JBL customer service.

Can I operate two coolers with one ProTemp CoolControl?

The ProTemp CoolControl is connected between the power supply and the ProTemp Cooler. It is therefore not possible to connect two coolers to one controller. Each Cooler needs its own controller.

The cooler does not cool down the aquarium

JBL ProTemp Coolers cool the water temperature by 2-4 °C in high ambient temperatures. To achieve this with this product, it’s important the maximum recommended aquarium volume is adhered to. Please note that the cooling effect only occurs when the cooler is in operation and that the system needs to have been running continuously for a few hours beforehand. The air flow needs to be directed across the entire width of the aquarium and be at a 45° angle to the water surface. If only a part of the water surface is ventilated or the angle is set to 90°, the desired effect will be lost or greatly reduced. The housing can be rotated 360°.

Can the CoolControl also regulate the new ProTemp Cooler x200 and x300 (generation 2)?

Yes, the CoolControl of the predecessor range can also regulate the new ProTemp Cooler x200 and x300 (generation 2) aquarium coolers.

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Blog (opinions & experiences)

JBL TV #41: Heat wave in the aquarium: The effective and inexpensive method for cooling the water

When the aquarium water temperatures are heading towards 30 °C in summer, it’s high time to add a cooling system.

Find out more

Cool the aquarium in summer - Reduce the water temperature with the JBL PROTEMP COOLER x300

The JBL fans (JBL PROTEMP COOLER) easily and efficiently lower the water temperature by about 4 °C

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Tips for cooling the aquarium - lowering the temperature

How do high temperatures affect our aquarium fish? And what can you do about it? Let us tell you!

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JBL TV #24: Aquarium heaters and aquarium coolers

What temperatures do our aquarium inhabitants have in the wild? How can you heat and cool your aquarium simply and effectively?

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Caution, Summer Heat! A Reason for Scaremongering?

You can’t prevent the temperature in your aquarium from rising. No matter what measures you take your living room will warm up on hot summer days and can even go over 30° C. So what can you do?

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Cooling Aquariums – Summer Heat in Aquariums

Summer means sweat, because even within our homes the temperature rises steadily. This can also be discerned in the aquarium.

Find out more


JBL aquarium cooler with improved technology

The JBL PROTEMP COOLERS are very popular in the hot summer months. They cool heated aquariums by up to 4 °C by generating evaporative cooling at the water surface and thus ensure the survival of fish, invertebrates and plants in the aquarium.

Find out more
Reference guide (Themeworld)

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Heating and cooling

Why is 25 °C ideal? This is how to heat or cool aquarium water


safety instructions

  • safety instruction for technical devices
    • Filename:
spare parts
Customer reviews


Overall rating: 4.8
10 public review(s) for this product.

1 Review


Excellent, Worth every penny!

I have used this product within the summer and I have to say, that it managed to beat the heat! My tank's temperature was in low levels 20-23 even though the rooms temperature was 30-32! You can check a review of this product on my instagram account " nemophilist_scaper "

9 more reviews in other languages

9 Reviews in other languages

A. Valais - German

Kühlt sehr gut und sehr schnell und ist nicht sehr laut und verbraucht fast kein Strom

Malawi-Cichliden-Portal - German

Ich habe den JBL PROTEMP Cooler x300 am Aufzuchtbecken im Einsatz, er ist ein feiner Helfer während der heissen Sommerzeit.

Er ist Stromsparend und Kühlt mein Aquarium in den heissen Sommertagen 3-4 Grad runter. Der Lüfter ist sehr ruhig und lässt sich Kinderleicht anbringen.

Ich finde ihn Top, nur schade das es den Kühler nicht für Becken ab 1000 Liter gibt.

Discus.forest - German

Hatte diesen Kühler über meinem Meerwasserbecken. Ich war total zufrieden damit !! Würde ich mir aufjedenfall wieder kaufen.

Aquarium_Zimmer - German

Ich habe dem JBL ProTemp Cooler x300

seit ein paar Wochen im Einsatz.

Der Lüfter läuft angenehm ruhig und lässt sich sehr flexibel anbringen.

Der Kühler hält mein Meerwasser Aquarium, trotz der höheren Außentemperatur, im passenden Bereich.

Smells_Like_Seawater - German

Mit diesem Kühlgebläse ist man super für den Sommer vorbereitet !!! Ich finde ihn echt klasse hat eine gute Leistung 👌

M. Alparslan - German

Ich habe es direkt mit der Controller im Betrieb genommen, es ist definitiv Geräuschearm als andere Hersteller. Stromsparend und bei mir hat es in den Sommertagen bis zu 3 Grad abgekühlt . Bin sehr zufrieden und möchte es nicht missen .

bennys riff welt - German

Ich hatte vorher andere Lüfter dran die 10x Lauter waren ich bin richtig zufrieden. Und werde jetzt ganz auf die Lüfter um stellen weil sie so Leise sind. Bin mir sicher Leiser geht schon nicht mehr und sie machen auch richtig gut Wind. JBL Beide Daumen hoch

cichlids_catalunya - Spanish

Ventilador excepcional, he conseguido bajar la temperatura incluso 6 grados. Un aparato genial, la única pega que veo es que hace un poco de ruido, no es completamente silencioso

Unterwasserwelt_Bautzen - German

Ein sehr guter Helfer, der tut was er verspricht. Im Schlafzimmer konnt ich ihn nicht nutzen, dafür aber im Wohnzimmer. Kann ich sehr empfehlen. 💪

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