I have had a 3 barrel system for a year now that consisted of a barrel for the fish tank, 2 half barrels with lava rock as grow beds, a half barrel as a DWC tank and a half barrel as the sump. This was a good model and worked well for about a year, but now I want more- grow space and fish.
The pictures show the progress to date. The first picture you can see the old location of the fish tank and 1 grow bed on the left and the new fish tank on the right with the second grow bed and DWC tank already on top of the new fish tank. The second picture shows the 10x10 final lay out as a U with the to be grow bed on the left and the fish tank on the right. I think is am going to keep the old grow beds on Top of the fish tank to help buffer the water levels in the new grow bed.