Overflow box with bottom water intels?

[xaacuetara]

Hi!
just bought a new tank and it comes with an internal overflow box which has top and bottom water intels. I’ve been working on plumbing it for the las days and those bottom intels make me wonder what are they meant for and also make me concern about the water level going to low (same level as the main drain pvc pipe) due to those bottom water intel, so any suggestion on how to plumb it?

Thanks for the help!

 

[Formulator]

I’m not quite understanding. Can you take some more pictures of the whole thing and where you are installing it?