Originally Posted by Calwax
i feel like sometimes when i try to use n2 gas to push the column that it kinda locks up the flow
Skyhighler is right that I answered your first question and didn't notice the second.
A six inch column is OK if you have enough flow and a shower head, but you most likely don't. Your flow will find the easiest way through, which is down he middle of the column. without fully wetting the outer edges of the column.
You can get full wetting with a bottom flood and a small supply, but not from the top and the fluid velocity washing away the boundary layer will be low.
You mention using a N2 push. Are you fully burping it off before recovery?
If not, recovery will be be slow because N2 is not condensable, only compressable, so your pump pulses are pushing against a spring action.
How long does it take to recover the LPG?