JBL ProFlora u402 *
CO2 plant fertiliser systems with disposable cylinder for freshwater aquariums

There are successor products for this item:
ProFlora u502
  • Optimal feeding of fast and slow growing plants for aquariums from 40 to 400 l (max. 120 cm)
  • Professional water care: solenoid valve with night switch-off. Precise dosing thanks to the pressure reducer. Ideal supply of CO2 due to extendable diffuser Taifun
  • Best CO2 amount control with bubble counter. Residual pressure display on pressure gauge
  • Safe: no slipping of hose thanks to hose screw connection, check valve prevents water entering the cylinder, anti-kink protection for hose
  • Contents: fertiliser system ProFlora u402, incl. dispos. CO2 storage cyl., solenoid valve, 2 m hose, anti-kink protection, pressure reducer, diffuser, bubble counter, CO2 perm. test, fertiliser. Storage cylinders available separately or in pack of 3
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Product information

Nutrition for aquarium plants
Healthy plants are important for every aquarium. Plants supply the aquarium with vital oxygen for the aquarium dwellers, prevent algae growth and remove pollutants.

Healthy plants = healthy fish
Healthy plants prevent algae growth, supply oxygen, remove pollutants, provide hiding places and reduce pathogens.

For the plants to flourish the following demands need to be met:
Light as energy source for the photosynthesis of CO2, nutrients and trace elements as growth promoters.

JBL fertilisers supply the plants with all main nutrients and essential trace elements through the water. This way the plants can absorb all the required nutrients they need over the leaves and roots.
The capacity of a CO2 system depends on various factors. The carbonate hardness, the quantity and species of the plants and the strength of the water surface movement are decisive.

This product is unfortunately no longer available

JBL ProFlora u402 *

Art. no.:
EAN Code:
500 g
400 l
Volume packaging:
28.240 l
Gross weight:
4920.000 g
Net weight:
3640 g
Weight factor:
135/465/450 mm

Technical Data

capacity from - to:60-400
Bluish discolouration despite increased CO2 supply

Owing to a production fault a green colour change may not occur with the batches 1000 and 1001, despite increased CO2 supply.

Should you have one of the above mentioned batches, you can request a new refill set free of charge upon presentation of the sales receipt and a photo of the batch number. Please contact our customer service under: https://www.jbl.de/support/

JBL ProFlora u500: How can I dispose of my disposable CO₂ cylinder?

You can either dispose of it with your general household rubbish or with scrap metal when it is empty. Ensure that the cylinder is completely empty.

Is it bad if water runs into the bubble counter?

If water runs back into the bubble counter, that’s not a problem as long as the water is not drawn towards the night time shut-off from there. The excess water is normally pressed out of the system again during the day.

JBL pH-Control: When the appliance is connected and switched on, there is often a pulse-like formation of enormous bubbles at the CO₂ - air stone, so that the fish become frightened. Afterwards, the desired formation of bubbles is present again. When the electromagnetic valve in the controller is switched off, the pressure in the entire system from the cylinder to the pressure reducer and the tubes and to the electromagnetic valve persists. When the valve is opened, the pressure in the system escapes first and then the system continues to operate as usual.

When the electromagnetic valve in the controller is switched off, the pressure in the entire system from the cylinder to the pressure reducer and the tubes and to the electromagnetic valve persists. When the valve is opened, the pressure in the system escapes first and then the system continues to operate as usual.

You can decrease / prevent this by reducing the operating pressure in your pressure reducer. In our new pressure reducers, this can be done with an Allen wrench under the black cover top.

Is the carbon dioxide in compressed gas systems dangerous ?

500 g of carbon dioxide are equivalent to 11.36 mol (1 mol of carbon dioxide weighs 44.01 g).

1 mol of an ideal gas occupies 22.4 l volume under normal conditions (normal air pressure and temperature), which means the following for 500 g of carbon dioxide:

11.36 x 22.4 l = 254.48 l.

A room of 20 m2 (4 m x 5 m) and a ceiling height of 2.5 m contains 50 m³ of air, which is 50,000 l.

Carbon dioxide is heavier than air and collects at the bottom under calm conditions. The gas would be 1.27 cm above the ground with 500 g of carbon dioxide.

Then, correspondingly, 4 times higher with 2 kg.

When the CO₂ is mixed with the air in the room, 254.48 l of carbon dioxide correspond to a concentration of 0.5 % of carbon dioxide with 50,000 l room volume of a room with a size of 20 m2 and a standard ceiling height, which is in the range of the maximum work place concentration for an 8-hour working day.

Accordingly, no excessive danger is associated with carbon dioxide compressed gas systems for aquariums.

Nevertheless, a few points should be observed when dealing with a compressed gas system:

1) Please be aware that the compressed gas cylinders must undergo a TÜV test regularly every 10 years.

2) Rusty cylinders, especially with rust near or on the bottom, should no longer be used, even if they have a valid TÜV mark.

3) Do not store the compressed gas cylinders in the sun, as this causes the internal pressure to rise. Normally, nothing will happen if you do, as the cylinders are constructed to withstand pressures up to 200 bar, but the bursting disk may burst, thereby causing all the gas to escape. In this case, do not touch the cylinder without hand protection, as the cylinder becomes very cold due to the drop in pressure.

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Plant care

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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

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

CO2 plant fertilisation

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Product tests & info

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safety instructions

Safety information
safety information in accordance with GHS
Hazard symbol
  • GHS04
Risk phrase
H280: Contains gas under pressure; may explode if heated.
safety note
P102: Keep out of reach of children.
P103: Read label before use.
P410+P403: Protect from sunlight. Store in a well-ventilated place.
P101: If medical advice is needed, have product container or label at hand.
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