Ok so I'm looking at an E-Shopps nano overflow box with a Hydor L30 Return pump. I've seen a similar setup on youtube and the user seems to enjoy it.

Couple of questions,

From the tank, I'll have a 1'' hose going into my sump, from there, it will exit my return pump through a 1/2'' outlet. With this being said, will I be looking at 1/2'' tubing or 3/4'' tubing coming out of my sump? Can you connect 1/2'' to 1/2'' vinyl tubing?

Next question, when I have the tubing going back into the display, how do I connect the vinyl tubing to the lockline? All the pieces I see seem to be threaded thanks again in advance