Evolution aqua

[Gotts6501]

So I've just bought an evolution aqua with twin overflow and inlet, the overflow is through the back of glass and has been converted to hard piping down to sump, do I need to do anything to stop airlocks? I'm unfamiliar with this setup as I've only had a weir system before
Thanks in advance

 

[lapin]

A picture would help. Its not a common tank

 

[Gotts6501]

This is it

 

[fish farmer]

I have an old Glassholes overflow with similar arrangement. They have a hole drilled in the top of the elbow with a piece of tubing extending upward.