That first BRS video at 2:50 he says don't tumble it "too vigorously" when you have GFO and carbon in the same reactor or the GFO will grind the carbon to dust. I didn't watch the whole video, I don't agree that the media should tumble to its entire depth. I posted a video on page 1 that shows the flow rate that I prefer. I do recommend though, that once a week the ball valve should be opened so the media can be flushed at which time it should tumble vigorously for maybe 30 seconds or so. This dislodges trapped detritus and prevents clumping and tunneling.
Here's the video again of the flow rate I recommend.
http://youtu.be/iE01NgvGHIY
This is getting somewhat off-topic rant-like.
