EHEIM glass CO2 diffuser for aquariums up to 600 L
Regular price
5,400.00 RSD
Regular price
Sale price
5,400.00 RSD
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per
1,800.00 RSD × 3 with no fees
Klarna.
The EHEIM CO2 diffuser breaks the gas up into fine bubbles that dissolve in the water instead of escaping at the surface. It suits planted aquariums of up to 600 litres.
Separate bubble counter and integrated non-return valve.
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The summary
- Which tanks it suits: planted aquariums of up to 600 L.
- What is included: glass diffuser, bubble counter and non-return valve.
- The dosage: about ten bubbles per minute per 100 L to start with.
- The installation: 4/6 mm pipe, fixed with suction cups.
Less gas lost at the surface, more CO2 for the plants
The EHEIM glass CO2 diffuser dissolves the gas in the water of a planted aquarium of up to 600 L, instead of letting it escape at the surface. It breaks the CO2 into fine bubbles and includes a separate bubble counter and a non-return valve. As a starting point, aim for around ten bubbles per minute per 100 L.
Once it leaves the regulator, the CO2 still has to dissolve in the water to benefit the plants. A large bubble that rises to the surface in a second escapes almost entirely into the air: the gas is lost, and your cylinder empties with no result. The diffuser breaks the CO2 into a multitude of fine bubbles, whose contact surface with the water is much greater, so that a large part of the gas dissolves before reaching the surface. The EHEIM one, made of glass, suits planted aquariums of up to 600 litres.
🫧 Diffuser, bubble counter and non-return valve
The set combines three functions. The glass diffuser, with a large diffusion surface, spreads the bubbles through a large tank. The separate bubble counter is placed on the pipe upstream: it shows the CO2 flow bubble by bubble, which lets you adjust it with the regulator valve. The integrated non-return valve stops aquarium water from flowing back into the CO2 installation when the gas is off, at night or when changing a cylinder.
As a starting point, aim for around 20 mg of CO2 per litre, which corresponds to roughly ten bubbles per minute for 100 litres of water. This figure is only a starting point: the amount you need depends on the lighting, the density of the plants and the water circulation. Strong lighting and fast-growing plants use more, whereas a dimly lit tank needs less. Adjust in small steps over several days, keeping an eye on how your fish behave and on the pH value.
Fish at the surface signal an excess
If your fish come to breathe near the surface after an increase in flow, the CO2 level is too high. Reduce the flow straight away, increase surface agitation, and go back to the previous setting before adjusting again.
📍 Where to place the diffuser
The diffuser connects to a 4/6 mm CO2 pipe and is fixed in a corner of the aquarium by its 2 suction cups. Place it low, close to the bottom, and ideally in the filter outlet current: the bubbles are then carried through the tank, which gives them more time to dissolve. Made of glass, it stays discreet in the layout.
A CO2 test to adjust according to a measurement
The bubble counter shows a flow rate, not the amount actually dissolved, which also depends on water circulation and on plant consumption. The dissolved CO2 drop test gives you that level: you know whether you are approaching the target of 20 mg/L, without exceeding what your fish can tolerate.
100 L planted tank
Around 10 bubbles per minute to start with.
300 L tank
About 30 bubbles per minute, to be adjusted.
Tank up to 600 L
The capacity of this model.
Night cut-off
The valve prevents water flowing back.
🔧 Setting up and maintenance
Take a planted 200-litre aquarium, lit for 8 hours a day and fitted with a CO2 cylinder with regulator and solenoid valve. You start at around 20 bubbles per minute on the bubble counter, which is one bubble every 3 seconds, with the CO2 switched on 1 hour before the lights come on. After a few days, if the fish stay calm and the pH drops by about 1 unit during the lighting period, the dose has been reached.
Over time, algae and limescale clog the porous part: the bubbles get bigger and the flow slows down. Regular cleaning, following the instructions, restores the diffuser's efficiency. It is for freshwater use only, and it can be combined with a pressure regulator, a solenoid valve to cut off the gas at night and, for automatic regulation, a pH controller. If you do not have a setup yet, the EHEIM pressurised CO2 kit includes the cylinder, pressure reducer, diffuser and pipe.
🌱 In aquaponics
Pressurised CO2 remains rare in aquaponics, because the fish and the bacteria in the filter already produce it continuously. It earns its place in a heavily planted aquaponics aquarium, where you grow demanding aquatic plants under strong lighting. An efficient diffuser then lets you use less gas for the same result, and so reduces the risk of overdosing for the fish. The article on regulating pH in an aquaponics system gives the target range, from 6.4 to 7.5.
Technical specifications
The essentials
- Water volume
- Up to 600 L
- Diffuser
- Glass, micro-bubbles
- Bubble counter
- Separate, to fit on the pipe
- Non-return valve
- Built-in
To budget for separately
- CO2 source
- CO2 cylinder and regulator
- Pipe
- 4/6 mm CO2 pipe
In the box
- 1 glass CO2 diffuser with non-return valve
- 1 bubble counter
- Suction cup mounts
Specifications and recommended dosage from the manufacturer EHEIM, recorded on 13/10/2026. Freshwater only.
Manufacturer and product safety
- Manufacturer
- EHEIM GmbH & Co. KG
- Postal address
- Plochinger Str. 54, 73779 Deizisau, Allemagne
- Contact
- info@eheim.com
- Website
- eheim.com
Information provided under Regulation (EU) 2023/988 on general product safety.
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Frequently asked questions
8 questions
6 key questions, 8 in the detailed view
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