OK...bio balls are good at providing a home for the bacteria that converts ammonia to nitrite and nitrite to nitrate. They do this quite well. What they do not do is process nitrate...they actually produce it. If you have enough LR
in your tank (1.5-2lbs per gallon) to handle the biofiltration, then you don't need the bioballs. LR
and a DSB
not only convert the ammonia/nitrite, they convert nitrate to nitrogen gas. So, bio balls are not bad, but they may not be the best tool for the job.