need overflow information

[bigfishtoo]

Hi, I have a 120 gallon with two built-in overflows in the back and each overflow box have 1" bulkhead and 3/4" bulkhead fitting. One is for pump return, but how do the drains to sump filter need to be set up inside the overflow box.
Do I need stand pipe and elbow on the sump drain? Do you have a diagram for piping a tank with overflows or web site I can look up.

thanks Les....