Noob chronicals - plumbing questions

[SaltyDog143]

We are almost ready to start plumbing, I plan on bring the tank to one of our local glass companies yo drill the back for my return line as I think it will look alot cleaner this way.

This is a 120gal tank, 48" x 24" x 24" with a rear external return. There are 2 - 2" return lines, not sure why 2 but it came that way. I will include some pictures, but my thoughts so far are to Y the two returns into one, install a gate valve to tune, tanke it down to the sump and T into two again before the filter socks. Does this sound reasonable? Is there a better way?

Next, the return line -
I have not picked up my return pump yet, but thinking I will use a 3/4" return line, intending to use a ball valve as a safety. Here is the part that I need help with on suggestions. The wall behind my tank backs onto my kitchen, if I run a line through the wall I can access the kitchen plumbing for a drain, ie draining during water changes or for an emergancy overflow drain to try to prevent flooding. This part I have no clue about, how would you guys handle this?

Slowly but surely getting closer
Randy
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