I'm setting up my fug using the Refugium Starter kit from AlgaeBarn. I just got my first shipment today and I'm curious on how to lay these media cubes in the fug section. I have enough cubes to cover the entire bottom of the fug section. Question is: Do I cover the entire bottom with the media cubes are lay them in a way so there are gaps in between each cube? If the gaps are required, how far about should they be roughly? Thank in advance!