Do I need to use special CO2 proof tubing or CO2 resistant tubing with my CO2 system?
We use the Aquarium Co-Op airline tubing (i.e., a flexible, black tubing made from food-grade PVC) on all of our aquariums and have not detected any perceptible loss of CO2. In our experience, special CO2 tubing is more expensive, harder to bend, and not as readily available.
For more information on CO2 systems in high tech planted tanks, read the full article.