Measurement and control computer for automatic CO2 addition and pH regulation

  • Regulates the addition of CO2 for perfect plant growth in the aquarium and the ideal pH value for aquarium fish
  • Connect temperature sensor, transformer and pH electrode (not included), connect to the solenoid valve, enter the wished pH value or use the automatic programme
  • Touch display enables easy operation through the operating menu. For automatic adjustment of CO2 addition, the carbonate hardness (KH) needs to be measured and entered.
  • The programme calculates the ideal pH value from the KH and the existing pH value and adds as much CO2 as necessary until the pH value is reached. Also displays the water temperature
  • Package contents: CO2 control unit with touch display, wall bracket, power supply unit, temperature sensor + suction holder, connecting cable to the solenoid valve, cuvette holder for calibration liquids
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Price: 287,68 €
Recommended retail price incl. VAT
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CO2 cylinder
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Product information

Healthy fish thanks to an ideal pH value
The acidity defines the pH value of the water. It needs to be constantly checked and adjusted as necessary to maintain the health of the fish and plants.

Technical information
Inc. temperature sensor, modern graphic display with touchpad, sensor check during each calibration, error diagnosis during failed calibration, permanent display: pH actual/set value, sensor voltage, temperature, calibration reminder in days/hours, valve status, precision of measurement, set point adjustment: freely selectable or automatic calculation by means of auto pH, automatic temperature compensation during measuring and calibration, hysteresis freely selectable (upper and lower deviation from switching point), alarm function pH (alarm range), alarm function temperature (range and set point alarm), selectable valve status, language selection: D/BG/F/NL/I/DK/E/P, reset function, universal power unit suitable for all common mains voltages worldwide

Why you need a pH control unit:
If you want to automate the CO2 supply, you can connect this CO2/pH computer (JBL PROFLORA CO2 CONTROL) instead of a timer for the night switch-off. You have to enter the carbonate hardness (KH) of your aquarium water once and then the computer calculates the matching pH value, which is adjusted by adding CO2. Then the computer regulates the solenoid valve and adds as much CO2 as necessary until the pH value calculated or wanted is reached. The solenoid valve is then closed and opened again so that the pH value remains stable. The pH measurement of the water is done via a pH electrode, which is NOT included in the set and needs to be purchased separately.This ensures that you do not receive an old electrode in the set, but always a factory-fresh one! It is also possible to enter a pH value manually instead of automatically, independently of the KH.



Art. no.:
EAN Code:
12 V
Volume packaging:
3.24 l
Gross weight:
681 g
Net weight:
456 g
Weight factor:
Packaging dimensions (l/h/w):
96/201/169 mm


Animal species: Arowana, Axolotl, Barbels, Bettas, Bichirs/reedfish, Blowfish, Catfish, Cichlids (South America), Crayfish, Danions, Discus, Dwarf shrimps, Flowerhorn, Goldfish, Gouramis, Guppy, Juvenile fish, Killifish, Livebearers, Loaches, Panchaxes, Rainbowfish, Snails, Spiny eels, Tetra, Veiltails, freshwater butterflyfish
Animal size: For all animal sizes
Volume habitat: For all aquariums
Material: plastic (PC) / semiconductor
Colour: white / black

Electronic label / illuminant

Mercury: No
Dimmable: No

Technical Data

Height:67 mm
Length:25 mm
Width:89 mm
May the JBL PROFLORA CO2 products only be used for the aquarium?

Yes, the JBL PROFLORA CO2 products are designed exclusively for use in the aquarium. The gas contained promotes plant growth and works with fine precision so that even the smallest quantities can be supplied to the aquarium. Constant operation and the safety of the fish are thus guaranteed.

What does the message INSTAB mean?

The message INSTAB indicates: instable sensor voltage: the sensor tip is dirty, the electrolyte has leaked from the sensor, the sensor tip is damaged.

Remedy: Clean the sensor head (see the respective instruction), put the sensor into the storage solution for 24 hours and repeat the calibration. If this does not work the sensor is defective and should be replaced.

What deviations during the calibration are usual and how are they connected to the temperature?

It is difficult to give a precise answer without information about the sensor, particularly the age of the sensor. Good sensors have deviations in the range from 0.02 to 0.05 pH levels when calibrating.

The input voltage differs for each sensor, as each sensor has its own individual properties. For the majority of our sensors, it is between -30 and +30 mV at pH 7.

Both input voltages (pH 7 and pH 4) are important when assessing the quality of a sensor. The greater the difference between these two values, the better the sensor and the precision of the measurement and control. The differences should be over 140-150 mV.

The temperature sensor should always be used during calibration. The pH level varies according to temperature, so that it is always best to measure the pH level with temperature compensation. The deviation is between 20 and 30 °C, 0.17 pH levels, and the relationship is nonlinear.

What does the message OFFSET mean?

The message OFFSET indicates: The sensor voltage at pH 7.00 is outside the limit value, the sensor is too old, the cable is defective, no sensor is connected or the calibration has been performed with buffer 4 solution.

Remedy: Check the sensor cable for any signs of damage and repeat the calibration. Take care to use the buffer solution correctly. If this does not work, replace the sensor and calibrate again.

What does DELTAV mean in the display?

This message indicates that the potential difference per full pH unit is smaller than 30 mV. The pH sensor is either too old, defective or was accidentally calibrated twice with the same buffer solution.

Remedy: Repeat the calibration and take care to use the buffer solution correctly. If this does not work, connect a new sensor and calibrate again.

Show more FAQs ...
Blog (opinions & experiences)

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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Why is CO2 such a good help when combating algae?

Algae are plants, but only very simple Algae are plants, but only very simple ones. CO2 fertilisation promotes the growth of the more complex plants and algae have no chance against them!

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Perfect plant growth in your aquarium with the JBL PROFLORA CO2 System

Carbon dioxide (CO2) is the main food for your aquarium plants. With the help of a CO2 system you supply your plants with enough CO2 so that they can grow vigorously and healthily.

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CO2, also called carbon dioxide, is the main nutrient for all plants.

Find out more
Reference guide (Themeworld)


With the guarantee extension JBL GarantiePlus you secure your extra-long extended 4-year guarantee from the date of purchase for your JBL product. Do not miss out on your extended guarantee claim!

Plant growth

Are your aquarium plants growing as well you want? Here’s how to achieve perfect plant growth

Reducing problematic water values

How to lower critical water values.

Deficiency symptoms

Here’s how to prevent deficiency symptoms in fish and plants

Algae control

Here’s how to combat algae successfully and lastingly.

Plant care

What maintenance measures do your aquarium plants need?

Daily care

How much daily or weekly care is involved? What are the basic maintenance measures for your aquarium?


Why is CO2 so important for plant care? What benefits does CO2 fertilisation provide?


Why do aquarium plants need to be fertilised?

Plant species

Which plant species suit your aquarium? What demands do the individual species have?

Installation technical items

How and where in the aquarium do you fix and install technical items? Tips and tricks for the installation of all technical aquarium products


Which aquarium plants are best? What’s the best way to plant them?

Marine water - technical items

What is the difference between a marine and a freshwater aquarium? What is especially needed for a marine aquarium?

CO2 plant fertilisation

How important is CO2 plant fertilisation? Why do your plants need additional CO2? How does a CO2 system work?

The marine aquarium

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Goldfish aquarium type JBL Goldfish Paradise®

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Additional product information and downloads

safety instructions

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


Overall rating: 5.0
6 public review(s) for this product.

1 Review


With this controller you can regulate the Co2 while also, maintaining your ideal pH! it is a great addition to every automated aquarium set up.

5 more reviews in other languages

5 Reviews in other languages

aquagoekhan - German

Benutze den pH Controller, um den pH - Wert in meinem Biotopaquarium (Rio Negro) permanent zu überwachen. Mit der dazugehörigen pH Sonde macht es eine souveräne Arbeit! Genaue Messergebnisse, eine einfache Handhabung und ein tolles Design sind wirklich gegeben!

Ein Top Gerät!

Ich empfehle es mit ruhigem Gewissen weiter!

J. Le lous - French

produit vraiment top

facile et tres complet

je vous le recommande

je l'utilise sur mon aquarium depuis plusieur mois et je suis super contant

really great product

easy and very comprehensive

I recommend it

I have been using it on my aquarium

I am super happy

H. PEKTAŞ - Turkish

Ich muss den pH-Wert in meinem Aquarium konstant halten, deshalb verwende ich dieses Produkt und bin damit zufrieden. vielen Dank JBL

aqua_mtc - German

Funktioniert bei mir in mehreren Aquarien wunderbar.

Keine Gefahr durch zu viel CO2 wegen falscher Einstellung, oder defektem Druckminderer möglich. Einfach in der Handhabung.

Dutch aquascaper - Dutch

Heerlijk aparaat, makkelijk installeren, en nooit meer omkijken naar je bellen per minuut enz.

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