Thank you! This has helped me a lot. Should I just plumb the trickle pipe straight down into the second sock? Or do I need to put a Tee on the full siphon and plumb it all in together somehow? And no I didn't glue any of the pipes in the overflow box. I thought that same thingYou can use some of what you have.
The bulkhead will "control" the flow amount.
Cut the big pipe in the overflow area. Cap with a screen. This will be full syphone with a gate valve below.
Looks like you glued the return. I would replace the bulkhead if you did. You can use the pipe if it's not glued. (doesn't need to be glued in the overflow box.. Where's it going to leak to?) lol.
The u" channel for the loc-line can be reused if you run the return over the back into the box.
Emergency line should be an 1" or less below the wier for less noise.