Live rock in bak pak protein skimmer

The rubble is not from my tank I am going to buy it from lfs is I put it in small group of 1/2 a pound of rubble every 3 weeks or should I just us bioballs and how much viniger per gallon of water to soak the skimmer in

 

Is the rubble cured at your LFS or is it dead? I would stay away from the bioballs (biobale), unless you are willing to break down the Bak-Pak at least twice a month to remove the gunk that will build up in it. To clean your skimmer, soak it in 3:1 ratio water to vinegar for 3 days. Or you can just soak it in strong vinegar for one day. Just remember to rinse it good and let it soak in fresh water for a day before you introduce it back into your system.