I built one out of a 60 qt rubbermaid container. I built it according to the diagrams on the ecosystems website. I put it in a closet behind my tank wall but above. I punched a couple of holes through the wall behind the tank stand to run the hoses. I'm pumping in from the sump and gravity returning there too. I just got the miracle mud substrate today and they say I have to run it for a week before I can plant algae. I'm running higher flow than is recommended on this message board caust the ecosystems people recommend 1000-2000 gph. I'm running about 500 gph. I'll post results after the algae is planted.
Good Luck With Your Project!! <img src="graemlins//urrr.gif" border="0" alt="[urrr]" />