Hello
@Flippers4pups
1st I want to say I love your Tank and Sump setup!
2nd Its caused a lot of frustration for me

I have been watching and learning on R2R since 2017 and finally at the end of 2019 started working on my first reef tank. When I finally got the go ahead from the boss, I bought a used 90 but she then decided she wanted a peninsula tank. So starting again, the end of February I ordered a Marineland 120 from my LRS and started to build my own stand. I bought a 40gal Breeder for a sump while waiting on the 120 to arrive (understandably it took almost 2 months to come in since they are up in NY area). Being new to the hobby I was trying to wrap my head around all that would be required for a sump and looking at all the great threads available when I came a crossed your build thread. My wife was siting behind me looking when all of a sudden everything changed.
She said "Hey you can do that" and nothing has been the same since

Even though I had my plan almost figured out, she is very stubborn and wore me down so now I am starting over and trying to figure out how I'm going to make this happen. Sorry for the long post in here but figured I would give you the story behind my questions.
I have many many questions I could ask you but to start I was wondering what size pipe you used for the drains and the return as well as the water change drain? It looks to me (looking at your pic below) the drains are 1 1/4 and the return is 3/4.
My 120 will have an Eclipse L overflow setup in a Bean Animal config and I'm still trying to decide how many pipe runs I'll need from the basement to the living room upstairs.
Again sorry for the long story line and thank you for any help.
Your basement setup is fantastic!