Plumbing for single tier system

[Doublehoppy]

I'm in the process of buying pieces to create a single tier 25L system. I'll be using a March pump for transferring between vessels.

Before I buy too much of the plumbing gear I'm wondering if there is any difference in operating or efficiency between 9.6mm or 12mm hose, or is it irrelevant? 

I already have a few barbs and quick connectors for 1/2" (12mm) hose so I'll stay with that if there's no difference.

 

Cheers  

[studio1]

12mm all the way!

[Doublehoppy]

12mm it is.

Cheers