I'm pretty sure that the nitrogen cycle works like this: living things produce nitrogen containing waste as ammonia in the case of fish/marine organisms. Bacteria convert that ammonia into nitrites, and then other species of bacteria convert nitrites into nitrates. As far as I know bio balls just provide a large surface area to grow these colonies of denitrifying bacteria. Nitrates can be converted into nitrogen gas which is as inert gas (makes up most of earths atmosphere), BUT the nitrate to nitrogen gas conversion only occurs by bacteria that require an anaerobic (no oxygen) environment. We are kinda stuck with nitrates as part of our tanks that must be removed by water changes unless we have deep sand beds or live rock that can supply that anaerobic environment.
, removing bio balls will just cause a spike in nitrites which are far more dangerous than nitrates. Just keep on the Pwc
on a weekly basis.