Ok so I had an idea and obviously it would scale to size of the tank, BUT what about using like a 12" piece of PVC about 1.5' in length, capped at the bottom for a base. Basically drill a holl in the side and glue in the line from the pump so that it swirls water around the sand and eventually over flows the top of the PVC pipe. This would be sitting right after a filter sock in a larger sump (again scale to size of tank/sump) Seems like an easy way to get a little something extra. Any pump size would work just put a T in the line with a valve on the open side to adjust how much pressure is being forced into the PVC pipe.
Thoughts? Good, bad, dumb idea, or pointless because.... ?