Reliable protection from CO2 leaks

Special Softflex CO2 hose

CO2 simply seeps through many hose materials. The special Softflex CO2 hose from DENNERLE consists of a special CO2-proof plastic to ensure that valuable CO2 arrives where it is needed - in the aquarium.

  • Special CO2-proof plastic
  • Hose diameter 4/6 mm
  • Highly flexible, easy to install
  • Pressure-proof up to 7 bar

CO2 losses with various types of hoses*

Hose type Annual leakages Factor 
Special Softflex CO2 hose Several g 1
Standard PVC air hose Several 100 g Softflex is 10 x more leak-proof
Silicone hose several 1000 g Softflex is 100 x more leak-proof

* Based on 2 m hose, counterpressure 30 cm water column (= 0.03 bar), measured outside of the water.


Why do backflows of water occur in CO2 hoses?

Figuratively speaking, CO2 is instinctively "driven" to dissolve in water whenever the opportunity arises. In the event of an interruption in the supply of CO2 to the aquarium (CO2 cylinder empty, cylinder valve closed, CO2 night cut-off valve active, etc.), the CO2 which is presently still in the hose will also dissolve in the aquarium water. This causes a vacuum in the CO2 hose, drawing aquarium water into the hose.

The special CO2 check valve from DENNERLE reliably protects valuable items of CO2 equipment such as the pressure reducer, CO2 cylinder, CO2 night cut-off valve, etc. from backflowing water.


Art. no.Length
30602 metres
30615 metres