I was hoping you could help me out a bit by answering some questions.
What is the main reason you have a refugium on your tank?
How is your's set up and do you like it that way or is it a PITA?
If you started over, what would you do differently?
What type of maintenance does it require and how often?
One more - How big should it be for a 125 gallon tank?
If I add one I would need a DIY to make it fit, and I'm trying to decide if it's worth the hassle. Here are a couple of links for more info about the tank. Will post some pics of the sump area as soon as I can get some. Thanks in advance!
Lorraine's Rebuilding of 125 gal Tank Christmas Tragedy in My Tank