The material is fine but your liquid distribution won't be. Round chambers tend to be hard to get right because of the varying water depths. If you go pipe nft style, use SQUARE vinyl or PVC porch post sheathing. Link:

Vinyl Porch Post -Bufftech PVC Plastic Structural Posts

Plain square 5x5" tube, cut 4" holes, hang 4" net pots in them.

Also check out vertical NFT cascading over hydroton. It's much cheaper to build. Example: http://boards.cannabis.com/grow-log/...-darkside.html