Thanks deadsled and samtheman
This set up is between his neighbors fence...and the west side of his building.


Here's another shot of the 4 - 40 gallon tubs (media beds)...




I tried to have 2 of the beds share a drain. The drain kept up, but, when 2 were draining at the same time, there was a little splashing...



...so I made separate drains for each one.