AKA wet/dry bio-filter.
Cecil, I would think a small aquarium air pump would be sufficiant to turn it---slow turning is ok (sometimes better) as long as it doesn't dry out entirely.
Maybe so, but with Option 2 the air pump specs call for more air production at 2.2 cfm/1 PSI pressure at 27 inches of water and the closest I could find in the AES catalog was a $325.00 pump. (Sweetwater SL56 page 45.)
I think more air is needed than an aquarium pump to also run a airlift system (two pipes from two drums) to move water from the clarifier back to the main tank since there is no water pump.
The water goes to the clarifier via a siphon. There are also airstones that provide aeration that must receive air from the pump. See below:
