Before I go through the trouble to plumb a refugium...

[TylerHaworth]

How beneficial do you folks think a 30 gallon dedicated refugium would truly be for my 150 gallon system?

[Dreaco]

I would guess any excess nutrient export would be better than none, not to mention the pods and critters you would get with it.

[Lord Treas]

I've heard that 10% is a minimum but of course the more you can get the better, usually space below the tank is the restricting issue.

[rtparty]

Not much in my experience. Refugiums aren't needed in my opinion as they are just another place for detritus to build up.
I ran one on my very first tank because it was the thing to do back then. I haven't ran one since and am now running bare bottom. That's the best choice I've made outside of ditching LEDs for my tank.

Sent from my Galaxy S3

[TylerHaworth]

What about just the added water volume, I've never ran a system of this size and I want it to be just right.

It's a 150 cube, and my sump will only hold about 15 gallons or so while in operation, so the increase in total water volume would be about 20%