On the indoor system, the pipes and feed lines carry the water, the wood never gets wet from it.
My outdoor systems are similar, but the cover boxes are built from pressure-treated wood that is meant for outdoor environments and then stained to increase water resistance.
This link has info on how I built that one.
https://steemit.com/gardening/@steempowergarden/home-gardening-with-hydroponics-my-main-outdoor-hydrogarden-system
Wow amazing work! really!
Thanks for sharing