Pipe sizing for herbie style overflow in weir

[Readytoreef]

Hi everyone, I'm in the process off getting a custom tank made,measurements are 4ft long 2ft width and height...I'm planning on running a herbie style overflow in weir with upstand piping...in the sump I'm planning of running protein skimmer,carbon rector and algae scrubber...the return Will t off to feed rector and waterfall scrubber and have outlet to return to first chamber of sump so I can close all valves and just let pump circulate sump when doing maintenance cleaning....the return will go into weir and t off at top and come out either side of weir with nozzles..I'm unsure of pump size at moment...I've been looking everywhere but can't find clear information...I need to know what size pipe do I need for main drain and emergency drain and pipe size for return..and does a 1inch bulkhead connect to 1 inch pipe I know sounds dumb or is bulkhead slightly bigger in size than pipe connecting to it...is 1 inch pipe ok for all 3 pipes?...any advice will kindly be appreciated....thanks

 

[Reefing Madness]