Pipe diameter vs flow rates (and more)

[CRAP! Another Hobby]

OK...totally scrapping the 55 g reef that we just spent hundreds of dollars on. "WHY?" you may ask...well ...because now we are going to use a 90 g for the reef and the 55 for the sump!

My question is this...OK, maybe a few questions...well...maybe more than a few questions

***NOTE*** Since it (the 90 g) is a Hagen tank...I am assuming that the bottom will be tempered (non-drillable) glass. I will need to make another "OVERFLOW PIPE" as I did for my discus tank.

Does it really matter if my pipe from the tank to the sump is 1", 1.5"...2"? (Any ideas what the flow rates are??)

How much Flow through the sump is "ideal?" (Not counting the slow flow fuge)

Pump recommendations?! Mag5/7/9???

SCWD...is it worth it?

More "sump" area than refuge...or the other way around??


Any and all advice is welcome