co2 tubing vs air tubing?

[scapegoat]

Hi just a quick one, is there a difference? One seem to be 3 times the price of the other but surely they are very similar if not the same thing?

 

[Alastair]

Two very different things, co2 tubing Is usually much tougher and less flexible so as to not expand with the pressure of the co2. For example if your using an inline co2 diffuser that requires high pressure, the normal air tubing would just keep expanding and not allowing the higher pressure to go through at a constant set rate......if that makes sense


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[Ian Holdich]

Normal air tubing also corrodes a lot easier when c02 is run through.it. This is another reason c02 tubing is a little tuffer.

 

[scapegoat]

cheers guys, that's saved me finding out the hard way

 

[ian_m]

Reason is CO2 is slightly soluble in non CO2 proof tubing. The CO2 diffuses, over time, into the rubber/plastic and both changes its dimensions and/or can harden/soften it depending on the type of rubber/plastic. This is why it is not recommended you place CO2 injection on the inlet of your external filter as CO2 can be absorbed by the filters rubber seals and they can expand & soften breaking the seal. Air line hardens with CO2 use.

 

[Pinkmummy79]

surely this wouldn't make any difference, the rubber seals are going to get the same amount of co2 whether it's injected before or after the filter, it's just diffused more but still there, I wouldn't have thought the fact that the gas is still in suspension or not would make any difference to non co2 proof elements of the filter?

 

[ian_m]

Its the gaseous CO2 that dissolves in the rubber as obviously its concentration is 100% rather than say 50 parts per million in the water.

 

[Henry]

You can get inert PVC tubing from pneumatic suppliers if there's one near you (or online). They tend to sell it far cheaper than any aquatics supplier. Be wary that once stretched, it won't go back to normal shape, so ends must be trimmed once removed from diffusers etc before replacing on any other receptacle.