Here's an example of a 29g sump I built for my 75. I wanted to have a larger refugium, so i opted for this design. Never had an issue with micro bubbles in the DT.
Getting better T. I would take another three inches from the skimmer chamber and put that into the fuge as well. No reason to have an excessive space 15" in the overflow chamber. 12" should work just fine. You'll benefit more with that space in the fuge.
And as for you Jaa, I'm going to put myself out on a limb here, but I think Tony was missing a question mark at the end of his statement, which would have made it a question, asking me if the new diagram was 'better Russ?'.
Your putting two mp40's??! I was thinking about getting two also but everyone's saying I dnt red that much but I want! Lol and also what kind if rocks are you useing?