I wouldn't recommend putting the Bio Balls or ceramic rings. It should come with 3 sponges...only put 1 in and the other 2 keep as spares/back ups. In my tank, 1st compartment has: Carbon/Phosban and the 2nd compartment has Chaeto...it is a macro algae, if you don't have a light back there then you can't keep it--just put some live rock rubble and live sand. Third compartment you can keep your heater and your powerhead.
