The first post only had one responder give a very adversarial opinion with absolutely no advice on any part of setting up or maintaining a DSB
and the other link didn't show up on my iPod.
As someone who has used a plenum style DSB
in more than one system successfully (one for over 10 years continuously) I can say that I had great success. That said, I've never heard anything about the type of DSB
you are using.
If you ever find any info on it I'd love to read it. A 7" DSB
using a mix of substrate types and sizes over a piece of un-elevated egg crate. Sounds crazy. lol I wish the gurus here would chime in on this one. You may want to make a thread on Reef Central and see what the consensus is there. I'm always up for learning something new. ^_^