Question on BA overflow direction

[Maxxingout]

I've been in the planning/building stages of my 75g reef tank. Though I'm sure I'll have more questions to come, right now I'm trying to decide on one part on the overflow.

My 29g sump from left to right has the skimmer section, followed by 3 baffles leading into the return and the refugium on the right. I'm trying to figure out if I should T off the main siphon going into the refugium with a valve to limit flow. Or have the secondary pipe go directly to refugium since this pipe will be low flow anyway? Thanks in advance.

 

[RocketEngineer]

You would do better to supply the refugium from the return pump instead of from the drains. That way any detritus in the drains settles out in the skimmer section of the sump where it is easier to remove during water changes. In the refugium such crud is hard to remove and can decompose to release nutrients later.

 

[Maxxingout]

Good point.