"Whats a fluidized bed?"
idea is moving media, if you can use a neutrally buoyant media (K1 as an example) in a chamber that is filled with water and media swirling around. The beneficial bacteria grows on the media, but only the healthy media thrives as it is tumbled and knocked about. If you do a youtube search there are several different methods/ media. Zeros out the ammonia spikes with feedings.