Yes but what would the difference be between the Bio Balls and the Live rock? I will make someone mad here.. None! Bioballs become live just like rock. The great thing about live rock is that they have both aerobic and anaerobic bacteria in them. Anaerobic bacteria is what is responsible for the break down of nitrates into nitrogen. If you do not keep the rock sbmurged and sllow alot of 02 to get into the rock this bacteria will not live. So, although do not advocate the use of bioballs I do say that unsubmerged Live rock with water just splashing on it is the same thing.
I have always said Bioballs cause nitrate spikes when in fact they do not. They just have nothing to help with the breakdown whereas Live rock and Live sand does.
My opinion, take it for what it is worth to you.