NewNeither.
Brain-2 return holes at bottom.
With 2 rows of 2. connected with an elbow and a tee to the return on the brain 1". then pump up from within res with submersible , up above the water level, out the res, to a "Y" then feed to each top of buckets again using a tee and an elbow. 1/2".
This is a waterfall type system . Gravity keeps the water level and it's always linear. whatever is pumped from the res Into the buckets, gets pulled back into the res through the returns.