hey c dizz ,
out of the 2 options you have there i like the 1st best . it can flow up to 3 times as fast back to the controller bucket w/ 6 inlets verses 2 , you can run pump faster = recur. faster .

i have kinda the same set up as your pic. 2 . but not ebb n grow . i just recur. mine 24/7 to keep p/h -n- ppm. the same in all buckets . i only have 2 rows of 2 buckets though . not 2 rows of 3 . when i set mine up like this i had worries of nutes being pumped from the controller to my rez. and right back down to the controller again -n- not drawing the nutes out of the buckets so well . i dyed plain water w/ foodcolors and ran sys. w/ a 120 gph pump at 3/4 the way up and it took 20 min. to draw all tinted water out . the longer the rows of buckets the longer it'll take too . when set up this way also there's very little room for movement n spacing/rearanging the buckets too .

my next grow i'm gonna try the manifold i posted the pic. but modified a lil . gonna have t fittings on all 4 corners and 2 valves . that way = 2 lines from rez. to plants and 2 lines into controller so recur. faster and each bucket has more range of movement cause you can run any length tube from manifold to the bucket then .

peace
crispi