I have a plenum as well...can't delve into the details as of now because I have to go somewhere tonight...
GARF sort of was my inspiration and I just took off with the idea. The biology/chemistry made sense to me and I knew others that had been succesful with them. I must say that I do not have the "Monaco" system only because I have also incorporated a fuge in with the plenum.
I will check back later on tonight on in the AM to see where this thread goes
Take er easy
Scott T.