I took the bio-balls out of my BC 14, because everyone warned that they were 'nitrate factories.'
The reason for this is that the
NH3 to
NO2 to
NO3 cycle is aerobic (notice you go from no O's to 3 O's). In a trickle filter, where water is being trickled over bioballs, there is a lot of water and air mixing together.
Therefore there is nothing inherently bad about a bioball. It is just a substrate with a large suface area. When its put into a high oxygen environment, the
Nitrates are produced more efficiently, and are back logged, because the next step (NO3 to Nitrogen) is anerobic. This is done by bacteria in low oxygen environments, such as inside of
live rock and in a deep sand bed.
The common wisdom is that, first off, bioballs are not necessary if you have
live rock, and secondly, they may cause you to have higher
nitrates.
