Can you teach me more? I thought NO3 is a sort of end product of the nitrifying process. NH3>NO2>NO3. Providing you do not overfeed in a coral tank, if you have no problem of NH3, which is a by product of fish waste or un-consumed food, why would you have NO3? In other words, if the input is minimal (NH3), why does it matter if you have bioring or not?