Board Thread:Questions and Answers/@comment-5847338-20130126051438/@comment-6055217-20130128084252

Cactus -> Cactus Green -> Water Proofing...just like any other waterproof piping.

http://tekkitlite.wikia.com/wiki/Waterproof_Pipes

Are you using regular cobble/stone pipes? Or are you using something different? In your picture it almost looks like Pneumatic_Tubes.