Now that I looked at the picture a little closer, it looks like this one was run by water pouring over the water wheel in the center.
You're right Cary. This one rotates via water pumped back from the clarifier and is know as "Option 1." You can do the same by turning the frame upside down and diffusing air up to the paddles from below. That is known as Option 2. I preferred option 2 but a good quality air pump with the right PSI and
CFM's was about $325.00. With Option 1 will have to add an aspirator or agitator but it's cheaper than the air pump.
The book this is in is outstanding and covers everything from RAS to cages to flow through and Aquaponics. For only about $25.00 it's well worth it.
Available on Amazon.com. The title of the book is Small Scale Aquaculture by Stephen Van Gorder.
