I actually removed all the bioballs from my wet/dry and replaced with LR rubble and then filled up the bottom of the sump, I was able to get about 20lb of rubble into the sump. This comes in handy since i've got 2 frag tanks and another on the way, so I have a fresh source of rubble for fragging and lots of biological for the tank. I left the plate in the ball container and filled it with rubble, once I've used all the rubble in the bottom of the sump, I transferr the ball compartment LR to the bottom of the sump and put new rubble in the ball area. Also got a lot chaeto and coralife 2x9w light over the wet/dry