Fluidized Bed Filter FBR / FBR

Biological filters work (mostly) with bacteria that settles on a filter material - the bacteria are living from passing substances. The larger the available surface the more bacteria are growing. But with increasing surface the danger of blocking rises up. Bakteria overgrow the total free space of the filter material and reduce the water supply. Consequently unwanted biological processes start (sulfate respiration, fermentation), that degrade the water quality dramatically.

Therefore a compromise between the available surface must be found or another technology has to be choosen.

The fluidized bed filter FBF / FBR combines a large surface for many filter bacteria with a small danger of blocking. The water velocity inside of the FBR is very high (upstream) that the filter material (quartz sand) is moving all the time. Bacteria settle on the surface of the sand grain and are supply best by the high water velocity (high conversion rate). If the bacterial layer gets to thick the upper bacteria are sheared-off by the colliding sand grains - a highly active biofilm remains. With this most effective technical process high oxidation power (filter power) at a small volumen is reached.

The FBF / FBR is best for all aquaria, that have a too less biological fitration: only a few living stones, less ground material, missing packed bed, missing trickling filter.

tipp Replace about half of the quartz sand each year. Over time, the grains of sand rub themselves round and lose surface area for the bacteria. Do not replace any more, otherwise the filter must be run in again, which can be accompanied by an ammonia increase.