In the rodinal semi stand disaster thread Gainer asked what is the definition of GENTLE agitation and what is its virtue. I have not got a clue ,but this is what I do: (1) I gently invert my paterson tank letting the developer flow smoothly through the reels just fast enough so that the dev does not froth or splash about. (2) I then swirl the tank anti-clockwice twice (3) The tank is returned upright and inverted again, this time I swirl it twice clockwise. (4) Once the tank is upright again I rap it twice on my worktop to remove air bubbles. I have always done this. Have I been missing something? Is there any good reason not to continue doing this?