I have had a fluval evo 13.5 gallon for over a year and a half and I have a bio cube ready to be setup. I have 20 lbs of sand and 13 pounds of rock in the fluval. What all will I need to setup the bio cube? Can I use the rock and sand that I already have? I also have coral and will I be able to add them to the tank the same day I set the bio cube up?