LR Rubble + Sponge Placement?

[slacknation]

Cycling my new 12g jbj nano dx. I removed one of the sponges in the first compartment. Should the sponge I leave in be at the bottom or should I bring it up to the top where the one I took out was sitting? I removed the bio balls and ceramic rings and have only the carbon bag left in second compartment, where do i place live rock rubble?

 

[aztec reef]

is your tank still cycling? if so then you don't have change the sponges just yet, but if already cycled then i would put the new sponge in the old compartment and visa versa. It's good that you remove the biobals.
as for the rubble i would just keep it in tank.