I'd run 4 of the long air stones in each of those puppies. I've done somme experimenting and the amount of bubbles do make a difference. I've done 6 DWC's systems of all sizes and the biggest tip is to ditch the walmart pumps and get one of the biggest pisten pumps you can. You really can't have too many bubbles. I know they are noisier but put out so much more bubbles. The other trick is the place your pumps wisely. Put them somewhere where they'll pickup fresh cool air so it will keep your res temps down.