Filter sock question

[Txag96]

So I have put a sock in my sump. (the sump is a very basic 10 gal tank with no dividers. It is fed by a hang on back overflow, has a small heater, a piece of chaeto, and a return pump. There is now skimmer yet.)
The sock is on one end and the return pump is on the other. I currently have the flex line feeding from the overflow into the sock delivering the water well below the waterline. My question is, Should the incoming water arrive below or above the waterline?
What are the benefits/downsides of each?

 

[ChrisAndJulie2012]

I have mine below the water line. Gets rid of the waterfall sound.

 

[b3ja]

I have mine below the water line. Gets rid of the waterfall sound.

And also the splashed.. Hate them