Does anyone know what GLA's CO2 resistant tubing is made out of? I cannot find any info on the GLA website. The description reads "This is NOT silicone tubing which is highly permeable to CO2." That's not really saying a whole lot. Would be nice to know what the material IS, not what it IS NOT. I guess we're just supposed to trust that the material is CO2 resistant...

Also, I'm curious as to the inner and outer dimensions of the tubing.

not sure about the material (it's definitely not silicone though) but here's help on the ID and OD. hope that offers some help

How long of a tubing run are you making?

Maybe 2 feet at the most.

Thanks, Apistia!

At 2 feet it really does not matter. I wouldn't go nuts looking for something special. That short of a run you won't really permeate that much imo. I have a real short run myself and nylon tubing works just fine.

Polyurethane tubing is sold at many aquarium sites for CO2.
It will still become brittle over time.
I use for Argon, Nitrogen, and CO2 at work.
Maybe a three year reliable life span, tends to fail at fittings.

Silicone tubing is required for ozone.

I'm having trouble with the tubing I'm currently using becoming brittle. I'm more concerned with solving that issue than I am about permeability.

Their tubing is standard size.
It mounted to my bubble counter and diffuser / reactor perfect.

I'm pretty sure all "airline" hoses become brittle after a while. Nature of the beast. Unless you used a soft silicone tubing which I don't believe is recommended for co2 for same reason regular silicone airhose isn't recommended. All airlines (air pump, co2 setup) I've ever used hardens over time, including gla's tubing.