if i was going to use a wet/dry filter as a sump and lets say i had live rock in the tank and a deep sand bed, would it matter if i had bioballs in the wet/dry? i have heard that the cause a buildup of one of the bad elements - nitrate, amonia, ? - but since i would have live rock to balance things out, would it matter? or should i have something else in the wet/dry besides bioballs?