JBL PROCRISTAL UV-C Compact plus 18 W
Compact UV-C water clarifier 18 W against water cloudiness

  • Crystal-clear and healthy water: 18 W UV-C water clarifier for the quick and efficient elimination of greenish and whitish cloudiness in freshwater and marine aquariums and in garden ponds
  • Space-saving assembly: connect to external filter or separate pump. Inlet and outlet are positioned for practical use. Shortest installation length: 42 cm
  • Partial sterilisation for aquariums up to 1500 litres (pump max. 400 l/h) /15,000 l pond (pump max. 4000 l/h), against floating algae up to 500 l in the aquarium (pump max. 500 l/h) / pond up to 4000 l (pump max. 4000 l/h)
  • TÜV tested, safety switch: UV-C bulb switches off automatically when the device is opened. Sturdy, UV-resistant casing, 2- glass-cylinder design
  • Package contents: complete UV-C device, 5 m cable, UV-C bulb 18 W, socket: 2G11, wall mount, V2A screws, nozzle hose connections for 12 - 40 mm hoses. Guarantee: 2 years (+2 years upon registration of the product)
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Price: 202,34 €
Recommended retail price incl. VAT
You can find this item in your specialist and online shop
Product information

Crystal-clear and healthy water
Poor light conditions, over-fertilisation or even a surplus of nutrients can have negative effects on the aquarium water and may promote algae growth. Floating algae lead to green, bacteria to white clouding. The JBL water clarifier eliminates cloudiness caused by bacteria and floating algae. The aquarium water passes through the sturdy, UV-resistant casing of the clarifier. The UV radiation kills off bacteria, other germs and floating algae as the water passes through. The efficiency of this UV-C water clarifier is particularly high, as the glass bulb is surrounded by a polished, reflective stainless steel foil, which reflects the UV-C radiation and thus doubles the efficiency. This can also help to eliminate persistent algae, such as thread algae, since their spores are also largely killed off.

No harmful side effects
No change of the water values / no negative influence on the essential cleansing bacteria in the filter.

Easy to install
Connect the water clarifier to the external filter or a separate water pump. Thanks to the 90° elbow included in the pack any installation position is possible.

The JBL UV-C Water Clarifier is TÜV tested and has a safety switch for an automatic switch off when the device is opened. The casing is UV-resistant, consists of sturdy walls and has an LED light that indicates whether the UV-C bulb is switched on.

Difference to the previous model JBL ProCristal UV-C Compact:
The function indicator light is now mounted on the flat side of the electrical unit and the microswitch for the automatic switch-off of the burner when the housing is opened (if the plug has not been removed) has been replaced by a magnetic safety switch. This means that the electrical units of the previous models (Compact) do NOT fit the new ones (Compact Plus) and vice versa.


JBL PROCRISTAL UV-C Compact plus 18 W

Art. no.:
EAN Code:
18 W
36,5 cm
Volume packaging:
13 l
Gross weight:
2776 g
Net weight:
2376 g
Weight factor:
Packaging dimensions (l/h/w):
165/210/377 mm


Animal species: Arowana, Axolotl, Barbels, Bettas, Bichirs/reedfish, Blowfish, Catfish, Cichlids (South America), Corals, Crayfish, Danions, Discus, Dwarf crayfish, Dwarf shrimps, Flowerhorn, Gobies, Goldfish, Gouramis, Guppy, Juvenile fish, Killifish, Koi, Livebearers, Loaches, Mussels, Newts, Panchaxes, Rainbowfish, Snails, Spiny eels, Sturgeons, Tetra, Veiltails, freshwater butterflyfish
Animal size: For all animal sizes
Material: Plastic/glass/copper
Colour: grey / black

Electronic label / illuminant

Mercury: No
Dimmable: No

Technical Data

power output in Watt:18 W
Height:141 mm
Length:442 mm
Width:246 mm
voltage:240 V
Are two seals on top of each other twice as tight?

The question itself sounds strange and the answer is not surprising. No, do not use two seals under any circumstances. If a seal is not tight, it may already have aged too much or be defective. Two seals on top of each other take up too much space and do not provide increased tightness, on the contrary. Therefore, replace a seal that does not work. By the way: with JBL SiliconeSpray you look after your seals and significantly improve their service life.

How often does the UV-C bulb need to be replaced?

How often a UV-C bulb needs to be replaced, for example in the JBL PROCRISTAL UV-C Compact plus units, depends on its operating system. After a maximum of 6000 - 8000 operating hours, the output will have dropped so far that a change is necessary. In the case of continuous operation (24 hours), a replacement will be necessary after 250 days. That’s why in ponds the bulb is best changed in spring while the technology is being restarted.

Is the UV-C bulb defective if it rattles and there is a small ball inside?

No, this bead consists of mercury and is absolutely necessary. The bulb is only defective if the ignition filament is torn.
After the lamp has been ignited, the temperature inside increases and liquefies this bead, creating mercury vapour. The resulting ionisation processes ensure the desired UV-C radiation to kill germs, bacteria and algae. Due to the mercury content, used UV-C bulbs may only be disposed of at appropriate collection points (e.g. for fluorescent tubes).

Why is combatting cloudiness less effective than partial sterilisation?

A partial sterilisation (against bacteria) is more effective than eliminating clouding caused by floating algae. Why? Because the cell structure of bacteria is quite simple. That’s why it is easier to destroy the cells of bacteria than those of algae.

How long does a UV-C device need to be in operation each day?

Without an onsite assessment we are unable to recommend how long your UV-C device needs to be in operation each day. For this we need to know the germ load and the regeneration level of the germ density in the aquarium. However based on values of our own experience we would recommend running the device for an absolute minimum of 12 h a day. A continuous operation is, however, better for the durability of the bulb.

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Blog (opinions & experiences)

Green water in the pond? JBL's PROCRISTAL UV-C helps - guaranteed

Unsightly and opaque green water colour in the pond (rarely in the aquarium) is caused by microscopic floating algae. There are two ways to combat these algae:

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JBL TV #49: Saving energy in the aquarium - reducing costs made easy

Yes, we can make energy savings in our aquarium, but not where most people think! In this video we show exactly where and how to save electricity costs.

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JBL TV #46: Clear view in the aquarium - Getting cloudy water clear

Biologist Heiko Blessin explains the causes of cloudy aquarium water and the ways to get it crystal clear again.

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Video: Replacing the UV lamp - Maintaining clear water in the pond and aquarium

With the help of a UV-C lamp, the water in the aquarium and pond becomes crystal clear and any cloudiness is eliminated within 24 hours. We will show you how easy it is to replace a UV-C burner.

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JBL TV #23: Cloudy water in the aquarium? These measures will help!

We’ll go through all the different types of cloudiness and discolouration, explaining how to treat each one.

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Video: How do you install a UV-C water clarifier?

We will show you how easy it is to assemble a UV-C water clarifier.

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The cold weather’s here: get your pond ready

Here you’ll find everything you’ll need to know to keep your fish healthy during the winter and to give them a good start into the next season.

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I’ve had enough of this pond! Give up or save it?

Maybe you’ve felt like this: nothing works, the pond looks disastrous and you just don’t know what to do.

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Let’s Clear This Up: Cloudy Water in the Pond

Clear water is right at the top of almost all pond owners’ wish list.

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The Indispensible Partner for a Good Pond Filter

In my opinion, a UV clarifier is an indispensible partner for a good pond filter. Unfortunately I am often confronted with dangerous half truths about this subject. First of all we need to say that the operating principle is the same or similar for every make.

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A Good Start to the Garden Pond Season

The temperatures are slowly beginning to rise again and the nights are nearly frost-free. This is the right time to carry out a quick check in our garden shed.

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Wussten Sie schon: Dass UV-C Wasserklärer Kalkmäntel bilden und dann nicht mehr funktionieren?

Wer seinen UV-C Wasserklärer irgendwann einmal öffnet, weil er in seiner Wirkung dramatisch nachgelassen hat, wird vermutlich etwas überrascht sein, dass die Glasröhre, in der sich der UV-C Brenner befindet, komplett von einer Kalkschicht bedeckt ist.

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safety instructions

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


Overall rating: 4.9
7 public review(s) for this product.

0 Reviews

7 more reviews in other languages

7 Reviews in other languages

Alexander Paulus - German

Sehr kompakt und super power!

Bin sehr zufrieden!

K. Buchgeister - German

Sehr begeistert!

Dieser UVC- Klärer macht genau das was er soll.

Mein Algenproblem hat sich in Luft aufgelöst und die Wasserqualität ist deutlich besser/ stabiler geworden.

Meine Diskus stehen seither deutlich besser da!

Ich werde nichtmehr auf den UVC- Klärer verzichten wollen

und obendrein spart man noch an Heizkosten ✅

german_monstertank - German

Tobis Aquaristikexzesse - German

Sehr guter UVC Klärer.

einfache Handhabung und Wechsel der Lampe schnell und unkompliziert. Ebenfalls ist es möglich durch ein Verbindungsstück nach bleiben mehrere UVC Klärer zu koppeln ,oder hintereinander in einen Filterkreislauf anzuschließen. Ebenfalls sind unterschiedliche Aufsätze erhalten die den Anschluss an unterschiedliche Filter- bzw. Schlauchgrößen ermöglichen, so kann der UVC Klärer auch bei Wechsel der Filter, oder Aquariengröße weiter benutzt werden.

Ein Stern Abzug da die Dichtungsringe gerne mal verrutschen und man bei Erstbetriebnahme hier kontrollieren muss das es nicht irgendwo tropft. Die neuen Dichtungsringe sind besser und verrutschen nicht so leicht.

Dichtungsringe direkt in den Schraubverbindungen wären mir lieber.

aquascaping.tv - German

Lampa spełnia swoja role. Należy jednak poświecić uwagę dokładnemu montażowi i zwróceniu większej uwagi na uszczelki. Należy po prostu zrobić to należycie. Polecam.

andres.reef - German

Top UVC Anlage.

Universal einsetzbar sowohl im Meerwasser, Süßwasser und im Teich.

Die Anlage ist bei Bedarf erweiterbar, sehr cool ist das Winkelstück um die Anlage im Unterschrank platzsparend unterzubringen.

Die Kabellänge beträgt 2 Meter, dies ist in der Regel innerhalb der Aquaristik mehr als ausreichend.

Ich selbst nutze es im Meerwasser Bereich und kann das Gerät ohne Bedenken weiterempfehlen !

diskusmummy - German

Ich habe den Cristal UV-C 18 Watt (250 Liter) und den großen Bruder mit 36 Watt (1000 Liter) im Einsatz. Beide laufen im Bypass meiner CristalProfi Filter zur Entkeimung mit. Ich mache regelmäßig Keimtests, um das Wasser zu überprüfen. Die Keimbelastung liegt bei10²KBE/ml - das ist ein super Ergebnis. Meine Diskusfische und ich werden nicht mehr drauf verzichten. Einziges Manko, die Brenner müssen regelmäßig getauscht werden. So what.

Kleiner Tipp: Man spart durch den UV-C Klärer auch an Heizleistung ;-)

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